Ambiguity in Statistical Analysis Methods and Nonconformity With Prespecified Commitment to Data Sharing in a Cluster Randomized Controlled Trial

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The Association between Message Framing and Intention to Vaccinate Predictive of Hepatitis A Vaccine Uptake

As ongoing, sporadic outbreaks of hepatitis A virus (HAV) infections present public health challenges, it is critical to understand public perceptions about HAV, especially regarding vaccination. This study examines whether message framing changes the intention to vaccinate against HAV and self-reported vaccine behavior. Using a randomized controlled trial (N = 472) in February 2019 via Amazon Mechanical Turk, participants were randomized to one of four HAV vaccination message groups or a no-message control group. The message groups varied in their emphasis on the nature of outcomes (gain versus loss) and for whom (individual versus collective). The message frames were compared by intention to vaccinate, differences in message characteristics, and behavioral determinants. There was no difference in intention to vaccinate between gain- versus loss-framed messages (MD = 0.1, 95% CI = -0.1, 0.3) and individual- versus collective-framed messages (MD = 0.1, 95% CI = -0.1, 0.3). The intention to vaccinate against HAV in the no-message control group was very similar to that in the message groups. However, gain-framed messages were rated more positively in valence than loss-framed messages (MD = -0.5, 95% CI = -0.7, -0.3), which may be helpful for cultivating a positive public perception of HAV vaccination. The study also highlights the importance of comparing message frames to a no-message control in designing health communication messaging promoting HAV vaccination.

Single Bolus r-SAK Before Primary PCI for ST-Segment-Elevation Myocardial Infarction

BACKGROUND

It is uncertain whether adjunctive thrombolysis is beneficial for patients with ST-segment-elevation myocardial infarction undergoing percutaneous coronary intervention (PCI) within 120 minutes of presentation. This study was to determine whether in patients presenting with ST-segment-elevation myocardial infarction a single bolus recombinant staphylokinase (r-SAK) before timely PCI leads to improved patency of the infarct-related artery and reduces the infarct size.

METHODS

This is an open-label, prospective, multicenter, randomized study. We enrolled patients aged 18 to 75 years who were within 12 hours of symptom onset of ST-segment-elevation myocardial infarction and expected to undergo PCI within 120 minutes. Patients were administered loading doses of aspirin and ticagrelor and intravenous heparin and were randomized to receive 5 mg bolus of r-SAK or normal saline intravenously before PCI. The primary end point was Thrombolysis in Myocardial Infarction flow grade 2 to 3 or grade 3 in the infarct-related artery 60 minutes after thrombolysis. The infarct size was detected by cardiac magnetic resonance 5 days after randomization. The safety end point was major bleeding (Bleeding Academic Research Consortium ≥3) during 30-day follow-up.

RESULTS

A total of 283 patients were screened from 8 centers and 200 were randomized (median age, 58.5 years; 14% female). The median symptom to thrombolysis time was 252.5 (interquartile range, 142.8-423.8) minutes and thrombolysis to coronary arteriography was 50.0 (interquartile range, 37.0-66.0) minutes. Patients randomized to r-SAK compared with normal saline more often had Thrombolysis in Myocardial Infarction flow grade 2 to 3 (69.0% versus 29.0%; P<0.001) and Thrombolysis in Myocardial Infarction flow grade 3 (51.0% versus 18.0%; P<0.001) and had smaller infarct size (21.91±10.84% versus 26.85±12.37%; P=0.016). There was no increase in major bleeding (r-SAK, 1.0% versus control, 3.0%; P=0.616).

CONCLUSIONS

A single bolus r-SAK before primary PCI for ST-segment-elevation myocardial infarction improves infarct-related artery patency and reduces infarct size without increasing major bleeding.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05023681.

Why Are We Weighting? Understanding the Estimates From Propensity Score Weighting and Matching Methods

BACKGROUND

Propensity score methods are used in observational studies to compensate for the lack of random allocation by balancing measured baseline characteristics between treated and untreated patients. We sought to explain the treatment effect estimates derived from different propensity score methods.

METHODS

We performed a retrospective analysis of long-term mortality after single internal mammary artery versus bilateral internal mammary artery (BIMA) conduit in 47 984 index isolated coronary artery bypass grafting procedures from 1992 to 2014 in the Northern New England Cardiovascular Disease Study Group registry using multivariable Cox regression, 1:1 propensity score matching, inverse probability weighting (IPW) among the treated, and IPW among the overall population treatment estimates.

RESULTS

The mean duration of follow-up was 13.2 (interquartile range, 7.4-17.7) years. In multivariable Cox regression, the adjusted hazard ratio for mortality was 0.83 (95% CI, 0.75-0.92) in patients receiving BIMA compared with a single internal mammary artery. The 1:1 propensity matched (hazard ratio, 0.79 [95% CI, 0.69-0.91]) and IPW among the treated (hazard ratio, 0.83 [95% CI, 0.75-0.92]) estimates showed a protective treatment effect of BIMA use on mortality. However, the IPW estimate of treatment effect for the overall population showed an increased risk of mortality after BIMA that was not statistically significant (hazard ratio, 1.08 [95% CI, 0.94-1.24]).

CONCLUSIONS

While the multivariable Cox regression, 1:1 propensity matching, and IPW treatment effect in the treated estimates demonstrate that BIMA was associated with a statistically significantly decreased risk of mortality, the IPW treatment effect in the average study population showed an increased risk of mortality associated with BIMA that was not statistically significant. This is attributed to the different populations (weighted to look like the overall study population versus treated group) represented by the 2 IPW approaches. Determining how the study population is balanced is a large driver of the treatment effect. Ultimately, the treatment effect estimate desired should drive the choice of the propensity score method.

Interpreting Randomized Controlled Trials

This article describes rationales and limitations for making inferences based on data from randomized controlled trials (RCTs). We argue that obtaining a representative random sample from a patient population is impossible for a clinical trial because patients are accrued sequentially over time and thus comprise a convenience sample, subject only to protocol entry criteria. Consequently, the trial's sample is unlikely to represent a definable patient population. We use causal diagrams to illustrate the difference between random allocation of interventions within a clinical trial sample and true simple or stratified random sampling, as executed in surveys. We argue that group-specific statistics, such as a median survival time estimate for a treatment arm in an RCT, have limited meaning as estimates of larger patient population parameters. In contrast, random allocation between interventions facilitates comparative causal inferences about between-treatment effects, such as hazard ratios or differences between probabilities of response. Comparative inferences also require the assumption of transportability from a clinical trial's convenience sample to a targeted patient population. We focus on the consequences and limitations of randomization procedures in order to clarify the distinctions between pairs of complementary concepts of fundamental importance to data science and RCT interpretation. These include internal and external validity, generalizability and transportability, uncertainty and variability, representativeness and inclusiveness, blocking and stratification, relevance and robustness, forward and reverse causal inference, intention to treat and per protocol analyses, and potential outcomes and counterfactuals.

Evaluation of randomised controlled trials published in Indian specialty dental journals for statistical testing of baseline differences: A meta-epidemiological study

Background

In randomised controlled trials (RCTs), the application of a test of significance to compare the baseline differences between the intervention groups is a common practice, though it has been condemned by many researchers.

Objective

This study aimed to assess the proportion of RCTs on human participants comparing the baseline differences between intervention groups using the test of significance in nine dental specialty journals published in India and to estimate the proportion of studies reporting baseline demographic and clinical characteristics in a table.

Materials and Methods

RCTs published in nine dental journals published by dental specialty associations of India were screened. A literature search was limited to the time duration of five years from 2017 to 2021.

Results

The authors analysed 326 RCTs. Of 326 RCTs published, 237 RCTs (72.7%) did not report the baseline demographic and clinical characteristics table. Tests of significance were applied to compare baseline differences between the intervention arms in 148 (45.4%) RCTs published.

Conclusions

Although criticised by the Consolidated Standards of Reporting Trials (CONSORT) statement, the majority of the trials published in dental specialty journals failed to avoid comparison of baseline differences with significance test and failed to report baseline characteristic table.

Intraoral clinical examinations of pediatric patients with anticipatory anxiety and situational fear facilitated by therapy dog assistance: A pilot RCT

OBJECTIVE

To evaluate whether the presence of a certified therapy dog specially trained for working in a dental setting may facilitate dental care of anxious pediatric patients.

METHODS

The Norwegian Regional Committee for Medical and Health Research Ethics approved a randomized cross-over trial with a study sample of n = 16 children aged between 6 and 12 years. The trial was registered on clinicaltrials.gov. Pediatric patients referred to specialist care at the Public Dental Service Competence Center of Northern Norway (TkNN) because of anxiety were invited to partake in the trial. Study participants met twice for an intraoral examination by a specialist pediatric dentist. Per random allocation, a therapy dog team was present in the clinic operatory during the clinical examination on the first or the second visit. The primary outcome was the assessment of patient compliance during the intraoral examination (yes/no). Secondary outcomes were measurements of child satisfaction and anxiety using the CFSS-DS scale (Dental subscale of Children's Fear Survey Schedule) completed by a parent/guardian. Supplementary outcomes were salivary cortisol level, heart rate variability, and skin conductance.

RESULTS

Ten boys and six girls (mean age 8.5) were recruited. All completed both clinical visits and demonstrated full compliance while undergoing a dental examination. All study participants and guardians reported great satisfaction. The salivary cortisol level reduction during the clinical examination on the first visit decreased by 30% in the presence of the therapy dog and 20% without, while the decrease during the clinical examination on the second visit was 29% in the presence of the therapy dog and 3% without. Within the limitations of the experimental setup, the electrophysiological measurements were unreliable in the current study population.

CONCLUSION

Dog-assisted therapy in a dental care setting appears to have a positive effect on children with dental anxiety or children that avoid dental care.

Comparison of virtual reality and physical simulation training in first-year radiography students in South America

INTRODUCTION

The aim of this study was to comparatively evaluate the learning outcomes achieved by first-year radiography students educated with either virtual reality (VR) simulation training or physical simulation training. The implementation of VR has been proposed to enhance learning in radiography students and provide a more effective and efficient approach to simulation. However, the learning outcomes achieved with this approach have not been widely investigated.

METHODS

Through stratified randomisation, 188 radiography students were allocated to one of two matched groups: a VR group (using Virtual Medical Coaching's Radiography simulation) and a physical simulation group (using Philips' X-ray equipment). Both groups were taught 31 radiography views over one 25-week semester. Both groups were assessed in an Objective Structured Clinical Examination (OSCE), using actors as patients in a physical X-ray environment. Assessment was conducted by assigning objective count scores for five assessment criteria.

RESULTS

The VR group achieved shorter OSCE duration and fewer errors in moving equipment and patient positioning: these results were statistically significant (P < 0.00). There was no significant difference in the frequency of errors in radiographic exposure setting between the VR and the physical simulation group. The current findings concur with the limited number of published studies concerning VR simulation in radiography.

CONCLUSIONS

The results of this study demonstrated superior effectiveness and efficiency in the VR group. This provides preliminary evidence to introduce VR simulation in the host institution and provide evidence that it may be possible to replace the use of physical simulation across other years of the degree. Further research investigating these possibilities is warranted.

Comparison of Patient Satisfaction and Safety Outcomes for Postoperative Telemedicine vs Face-to-Face Visits in Urology: Results of the Randomized Evaluation and Metrics Observing Telemedicine Efficacy (REMOTE) Trial

INTRODUCTION

There is a need to better understand the role of postoperative care via telemedicine (TM). We evaluated patient satisfaction and outcomes of postoperative face-to-face (F2F) versus TM visits for adult ambulatory urological surgeries in an urban academic center. Methods:This was a prospective, randomized controlled trial. At surgery, patients undergoing ambulatory endoscopic procedures or open surgery were randomized 1:1 to a postoperative F2F or TM visit. After the visit, a telephone survey assessing satisfaction was administered. Primary outcome was patient satisfaction; secondary outcomes were time and cost savings, and 30-day safety outcomes. Results:A total of 197 patients were approached; 165 (83%) consented and were randomized-76 (45%) to F2F and 89 (54%) to TM cohorts. There were no significant differences in baseline demographics between the cohorts. Both cohorts were equally satisfied with their postoperative visit (F2F 98.6% vs TM 94.1%, p=0.28) and found their visit to be an acceptable form of health care (F2F 100% vs TM 92.7%, p=0.06). The TM cohort saved a significant amount of time (TM 66.2% spent <15 minutes vs F2F 43.1% spent 1-2 hours, p <0.0001) and money (44.1% TM saved $5-$25 vs 43.1% F2F spent $5-$25, p=0.041) associated with travel. There were no significant differences in 30-day safety outcomes between the cohorts. Conclusions:TM for postoperative visits after ambulatory adult urological surgery saves patients time and money without compromising satisfaction or safety. TM should be offered as an alternative to F2F for routine postoperative care for certain ambulatory urological surgeries.

Distribution-Free Approach to the Design and Analysis of Randomized Stroke Trials With the Modified Rankin Scale

BACKGROUND

Many methods have been suggested for analyzing the modified Rankin Scale (mRS). However, there lacks a unified approach to analysis and sample size determination that properly uses the ordinal nature of the data. We propose a simple method for CI estimation and corresponding sample size determination.

METHODS

We quantify treatment effect by the win probability (WinP) that a randomly selected patient in the treatment group has an equal or a better mRS score than a patient in the control group. Thus, a win probability of 0.5 means no effect, likened to a draw in competitive sports. We estimate the win probability and its SE based on the ranks of mRS scores, where tied scores are handled by average ranks. Corresponding methods for hypothesis testing, CI estimation, and sample size determination are derived. The methods are evaluated with a simulation study based on real data from 10 randomized stroke trials that used mRS as the outcome measure.

RESULTS

Simulation results demonstrated that the methods performed very well in terms of CI coverage, tail errors, and assurance to achieving the prespecified precision. Because the methods are very simple, we implemented them in an Excel spreadsheet, requiring only user inputs on frequencies of mRS scores in 2 comparison groups.

CONCLUSIONS

Sound statistical methods are important for the success of randomized stroke trials. The proposed methods and associated spreadsheet should prove useful for stroke researchers in the planning and analysis of randomized trials. Meta-analysis has also been made easy for trials with ordinal scores.

Hip Hemiarthroplasty: The Misnomer of a Narrow Femoral Canal and the Cost Implications

Objective

Hemiarthroplasty has been identified as the treatment of choice for displaced intracapsular femoral neck fractures. A modular prosthesis is sometimes preferred for its sizing options in narrow femoral canals, despite its higher cost and no advantage in clinical outcomes. Thus, in this study, we investigated the factors affecting surgeons’ choice of prosthesis, hypothesizing that modular hemiarthroplasty is overused for narrow femoral canals compared to monoblock hip hemiarthroplasty.

Methods

A retrospective study of a regional level 1 trauma center was conducted. Patients who had sustained femoral neck fractures from March 2013 to December 2016 were included in this study. Inclusion criterion was modular hemiarthroplasty for a narrow femoral canal. A matched group of patients who underwent monobloc hemiarthroplasty (MH) was created through randomization. The main outcome measurements were sex, age, Dorr classification, and femoral head size. We measured the protrusion of the greater trochanter beyond the level of the lateral femoral cortex postoperatively. Modular hemiarthroplasty patients were templated on radiographs using TraumaCad for Stryker Exeter Trauma Stem (ETS®).

Results

In total, 533 hemiarthroplasty procedures were performed, of which 27 were modular for a narrow femoral canal. The ratio of modular to monobloc was 1:18. Average head size was 46.7 mm ± 3.6 mm for monobloc and 44.07 ± 1.5 for modular (P= 0.001). There were four malaligned stems in the monobloc group versus 14 in the modular group (P= 0.008). Unsatisfactory lateralization was noted in 18 patients (7 mm ± 2.9 mm) in the modular group compared with 8 (4.7 mm ± 3.9 mm) in the monobloc group (P= 0.029). Dorr classification was A or B in 24 patients in the modular group and 18 in the monobloc group (P = 0.006). Templating revealed that modular was not required in 25 patients.

Conclusions

As per our findings, it was determined that patients with a narrow femoral canal intraoperatively should not receive modular hemiarthroplasty. This is especially true for female patients with small femoral head and narrow femoral canal dimensions (Dorr A and B). They would require extensive careful planning. Surgical techniques should be explored through education intraoperatively to achieve lateralization during femoral stem preparation. This may avoid prolonged anesthetic time and achieve potential cost savings.

Effect of Adjusted Antiplatelet Therapy on Preventing Ischemic Events After Stenting for Intracranial Aneurysms

BACKGROUND AND PURPOSE

This study tests whether patients with unruptured intracranial aneurysm who underwent stent placement benefitted from platelet function monitoring-guided adjustment of antiplatelet therapy.

METHODS

We conducted a randomized, open-label, parallel group, assessor-blinded trial. Patients with unruptured intracranial aneurysm who underwent stent placement were assigned in a 1:1 ratio to receive either drug adjustment (patients who had high on-treatment platelet reactivity to antiplatelet therapy on the basis of platelet function monitoring [monitoring group]) or conventional therapy (without monitoring and drug adjustment [conventional group]). The second monitoring was performed 14 days after randomization in patients with drug adjustment. The primary outcome was the composite frequency of ischemic stroke, transient ischemic attack, stent thrombosis, urgent revascularization, and cerebrovascular death within 7 days after stent implantation. The safety outcome was the composite frequency of major, minor, or minimal bleeding within 1 month after stent implantation.

RESULTS

In total, 314 patients were included (n=157 per group). The primary combined outcome occurred in 19 patients (12.1%) in the conventional group and 8 patients (5.1%) in the monitoring group (hazard ratio, 0.39 [95% CI, 0.17-0.92]; P=0.03). Ischemic stroke occurred at a lower frequency in the monitoring group compared with that in the conventional group (4.5% versus 12.1%; hazard ratio, 0.34 [95% CI, 0.14-0.83]; P=0.01), which drove the overall primary combined outcome. The safety outcome occurred in the monitoring group (7.0%) and in the conventional group (1.9%; hazard ratio, 3.87 [95% CI, 1.06-14.14]; P=0.03). A significant difference was observed in the frequency of minor or minimal bleeding events between the two groups (monitoring group versus conventional group, 6.4% versus 1.3%; P=0.02) but not in the frequency of major bleeding events between the two groups.

CONCLUSIONS

Platelet function monitoring-guided antiplatelet therapy reduces thromboembolic events in patients with unruptured intracranial aneurysm after stent placement, significantly enhancing minor or minimal bleeding events but not major bleeding events. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03989557.

Efficacy of an online course in developing competency for prescribing balanced diet by medical students: A non - inferiority trial

Background

In the COVID era, medical education has been hit hard. Paradoxically, the need for health professionals has increased. Online methods are being widely used, but its efficacy is rarely measured.

Objectives

This study was conducted to find the efficacy of an online course in developing competency among medical students to prescribe balanced diet.

Methods

An online module was hosted at https://drzinia.moodlecloud.com/. A noninferiority trial was conducted among voluntary participants of the third MBBS students, in 2019. Stratified block randomization was done, so that ten students were allocated to the intervention arm of online sessions and ten students were allocated to the control arm of classroom sessions. Pretest assessments, seven assessments related to sessions conducted, and a postassessment were done. Generalized estimating equations were done to adjust for the effects of other confounders and see whether the intervention was a significant determinant of ability to prescribe balanced diet.

Results

Baseline variables were comparable in the two groups. The pretest scores were not significantly different in the two groups. The mean total marks scored by the online group (47.33/70) was not significantly different (t=0.68; p=0.50) from that of the class room group (45.70/70). The posttest scores were significantly higher than the pretest scores. Ninety-percent of students in the online course agreed that they could effectively learn through an online course.

Conclusion

Online teaching is effective to learn the prescription of balanced diet. Similar efforts in other domains can make medical education evidence based in the current scenario.

Mendelian Randomization in Cardiovascular Research: Establishing Causality When There Are Unmeasured Confounders

Mendelian randomization is an epidemiological approach to making causal inferences using observational data. It makes use of the natural randomization that occurs in the generation of an individual's genetic makeup in a way that is analogous to the study design of a randomized controlled trial and uses instrumental variable analysis where the genetic variant(s) are the instrument (analogous to random allocation to treatment group in an randomized controlled trial). As with any instrumental variable, there are 3 assumptions that must be made about the genetic instrument: (1) it is associated (not necessarily causally) with the exposure (relevance condition); (2) it is associated with the outcome only through the exposure (exclusion restriction condition); and (3) it does not share a common cause with the outcome (ie, no confounders of the genetic instrument and outcome, independence condition). Using the example of type II diabetes and coronary artery disease, we demonstrate how the method may be used to investigate causality and discuss potential benefits and pitfalls. We conclude that although Mendelian randomization studies can usually not establish causality on their own, they may usefully contribute to the evidence base and increase our certainty about the effectiveness (or otherwise) of interventions to reduce cardiovascular disease.

Interference Spreading through Random Subcarrier Allocation Technique and Its Error Rate Performance in Cognitive Radio Networks

In this letter, we investigate the idea of interference spreading and its effect on bit error rate (BER) performance in a cognitive radio network (CRN). The interference spreading phenomenon is caused because of the random allocation of subcarriers in an orthogonal frequency division multiplexing (OFDM)-based CRN without any spectrum-sensing mechanism. The CRN assumed in this work is of underlay configuration, where the frequency bands are accessed concurrently by both primary users (PUs) and secondary users (SUs). With random allocation, subcarrier collisions occur among the carriers of primary users (PUs) and secondary users (SUs), leading to interference among subcarriers. This interference caused by subcarrier collisions spreads out across multiple subcarriers of PUs rather than on an individual PU, therefore avoiding high BER for an individual PU. Theoretical and simulated signal to interference and noise ratio (SINR) for collision and no-collision cases are validated for M-quadrature amplitude modulation (M-QAM) techniques. Similarly, theoretical BER performance expressions are found and compared for M-QAM modulation orders under Rayleigh fading channel conditions. The BER for different modulation orders of M-QAM are compared and the relationship of average BER with interference temperature is also explored further.

Using automated pump-delivery devices to reduce the incidence of excessive fluid administration during pediatric dental surgery: a randomized-controlled trial

PURPOSE

The harms caused by excessive perioperative intravenous (IV) fluid administration are both well recognized and avoidable. The purpose of this study was to compare the incidence of excess intraoperative fluid administration in pediatric dental surgery patients when either an automated pump-delivery device or a manual gravity-drip device is used.

METHODS

We randomly assigned American Society of Anesthesiologists physical status I and II pediatric dental surgery patients to receive IV fluid via either a manual gravity-drip or automated pump-delivery device. Prior to each case, the attending anesthesiologist determined the target volume of maintenance IV fluid to be administered based on patient weight, estimated fluid deficits, and expected case length. The intraoperative IV fluid delivered was determined at the end of the case by the change in the IV bag weight. The primary outcome was the proportion of procedures that delivered ≥ 10% of the target IV fluid volume.

RESULTS

We recruited 105 children aged two to 12 yr (n = 49 in the automated pump-delivery device; n = 53 in the manual gravity-drip device). The proportion of excessive fluid administration was 8/49 (16%) in the automated pump-delivery device group compared with 33/53 (62%) in the gravity-drip group (relative risk of excessive fluid administration, 0.26; 95% confidence interval, 0.13 to 0.51; P < 0.001).

CONCLUSION

Intraoperative fluid administration using an automated pump-delivery device decreased the incidence of excessive IV fluid administration in pediatric dental surgery patients.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03312452); registered 17 October 2017.

Detecting the extent of control over selection bias relating to oral health and otorhinolaryngology: cross-sectional study

BACKGROUND

The authors of randomized controlled trials will usually claim that they have met the randomization process criterion. However, sequence generation schemes differ and some schemes that are claimed to be randomized are not genuinely randomized. Even less well understood, and often more difficult to ascertain, is whether the allocation was really concealed.

OBJECTIVE

To detect the extent of control over selection bias, in a comparison between two Cochrane groups: oral health and otorhinolaryngology; and to describe the methods used to control for this bias.

DESIGN AND SETTING

Cross-sectional study conducted in a public university in São Paulo, Brazil.

METHODS

The risk of selection bias in 1,714 records indexed in Medline database up to 2018 was assessed, independent of language and access. Two dimensions implicated in the allocation were considered: generation of the allocation sequence; and allocation concealment.

RESULTS

We included 420 randomized controlled trials and all of them were evaluated to detect selection bias. In the sample studied, only 28 properly controlled the selection bias. Lack of control over selection bias was present in 80% of the studies evaluated in both groups.

CONCLUSION

The two groups were similar regarding control over selection bias. They are also similar to the methods used. The dimension of allocation concealment appears to be a limiting factor with regard to production of randomized controlled trials with low risk of selection bias. The quality of reporting in studies on oral health and otorhinolaryngology is suboptimal and needs to be improved, in line with other fields of healthcare.

Disclosing genetic risk for Alzheimer's dementia to individuals with mild cognitive impairment

INTRODUCTION

The safety of predicting conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia using apolipoprotein E (APOE) genotyping is unknown.

METHODS

We randomized 114 individuals with MCI to receive estimates of 3-year risk of conversion to AD dementia informed by APOE genotyping (disclosure arm) or not (non-disclosure arm) in a non-inferiority clinical trial. Primary outcomes were anxiety and depression scores. Secondary outcomes included other psychological measures.

RESULTS

Upper confidence limits for randomization arm differences were 2.3 on the State Trait Anxiety Index and 0.5 on the Geriatric Depression Scale, below non-inferiority margins of 3.3 and 1.0. Moreover, mean scores were lower in the disclosure arm than non-disclosure arm for test-related positive impact (difference: -1.9, indicating more positive feelings) and AD concern (difference: -0.3).

DISCUSSION

Providing genetic information to individuals with MCI about imminent risk for AD does not increase risks of anxiety or depression and may provide psychological benefits.

Extended Protective Shield Under Table to Reduce Operator Radiation Dose in Percutaneous Coronary Procedures

BACKGROUND

Different tools and devices are effective to reduce operator radiation exposure at thorax level during percutaneous coronary procedures, but the operator radiation dose received at pelvic region still remains high. Our aim was to evaluate the efficacy of under-the-table adjunctive shields to reduce operator radiation exposure during percutaneous coronary procedures Methods and Results: The EXTRA-RAD study (Extended Protective Shield Under Table to Reduce Operator Radiation Dose in Percutaneous Coronary Procedures) is a prospective, single-center, randomized study. Patients who underwent transradial coronary procedures were randomized into 2 groups: group 1 (standard arrangement) and group 2 (adjunctive anti-rx shield under the angiographic table). In group 2, a further randomization was performed to compare 2 different under-the-table shields (a small curtain and a drape). A total of 205 procedures (122 diagnostic coronary angiographies and 83 percutaneous coronary interventions) performed in 157 patients by 4 different operators were included without significant differences in clinical and procedural characteristics between groups. The use of adjunctive shields was associated with lower radiation dose compared with no shield at pelvic region (42 µSv [14-98] in group 1, 13 µSv [5-27] in group 2; P<0.0001) and also at thorax level (4 µSv [1-13] in group 1, 2 µSv [1-4] in group 2; P=0.001). The reduction in dose was observed in all the operators. No significant differences were observed in pelvic dose using the 2 different shields ( P=0.183).

CONCLUSIONS

The use of adjunctive anti-rx shields under the angiographic table during transradial coronary procedures is associated with a significant lower radiation dose to operators at pelvic and thorax level.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03259126.

[Development of a Method for Assignment Control in Randomized Controlled Trials]

Randomized controlled trials (RCT) are the most reliable study design for causality estimation in medical research. Proper implementation of the process of randomization is necessary to ensure the reliability of RCT. In order to do so, 1) generation of randomization sequence, 2) allocation concealment, and 3) allocation must be properly implemented. Methods such as the central secretariat method, the envelope method, and the sequentially numbered container method are adopted to secure proper implementation. For investigator-initiated clinical research and relatively small-scale clinical research, the envelope method and the sequentially numbered container method are often adopted because of budgetary reasons, but these methods do not assure the implementation of proper RCT. Therefore, we designed an assignment management note system as a new method to manage the assignment of RCT that can be implemented in small scale clinical research. In this paper, we compare the assignment management note system with the conventional method from the viewpoint of the procedure necessary for the proper implementation of RCT, and discuss the advantages and limitations of the assignment management note system.

Blood Pressure Control and the Association With Diabetes Mellitus Incidence: Results From SPRINT Randomized Trial

The SPRINT (Systolic Blood Pressure Intervention Trial) demonstrated reduced cardiovascular outcomes. We evaluated diabetes mellitus incidence in this randomized trial that compared intensive blood pressure strategy (systolic blood pressure <120 mm Hg) versus standard strategy (<140 mm Hg). Participants were ≥50 years of age, with systolic 130 to 180 mm Hg and increased cardiovascular risk. Participants were excluded if they had diabetes mellitus, polycystic kidney disease, proteinuria >1 g/d, heart failure, dementia, or stroke. Postrandomization exclusions included participants missing blood glucose or ≥126 mg/dL (6.99 mmol/L) or on hypoglycemics. The outcome was incident diabetes mellitus: fasting blood glucose ≥126 mg/dL (6.99 mmol/L), diabetes mellitus self-report, or new use of hypoglycemics. The secondary outcome was impaired fasting glucose (100-125 mg/dL [5.55-6.94 mmol/L]) among those with normoglycemia (<100 mg/dL [5.55 mmol/L]). There were 9361 participants randomized and 981 excluded, yielding 4187 and 4193 participants assigned to intensive and standard strategies. There were 299 incident diabetes mellitus events (2.3% per year) for intensive and 251 events (1.9% per year) for standard, rates of 22.6 (20.2-25.3) versus 19.0 (16.8-21.5) events per 1000 person-years of treatment, respectively (adjusted hazard ratio, 1.19 [95% CI, 0.95-1.49]). Impaired fasting glucose rates were 26.4 (24.9-28.0) and 22.5 (21.1-24.1) per 100 person-years for intensive and standard strategies (adjusted hazard ratio, 1.17 [1.06-1.30]). Intensive treatment strategy was not associated with increased diabetes mellitus but was associated with more impaired fasting glucose. The risks and benefits of intensive blood pressure targets should be factored into individualized patient treatment goals. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01206062.

Cardiovascular Safety and All-Cause Mortality of Methoxy Polyethylene Glycol-Epoetin Beta and Other Erythropoiesis-Stimulating Agents in Anemia of CKD: A Randomized Noninferiority Trial

BACKGROUND AND OBJECTIVES

Erythropoiesis-stimulating agents correct anemia of CKD but may increase cardiovascular risk. We compared cardiovascular outcomes and all-cause mortality associated with monthly methoxy polyethylene glycol-epoetin beta with those of the shorter-acting agents epoetin alfa/beta and darbepoetin alfa in patients with anemia of CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a multicenter, open-label, noninferiority trial in which patients were randomized to receive methoxy polyethylene glycol-epoetin beta or reference erythropoiesis-stimulating agents, stratified by maintenance or correction treatment status and C-reactive protein level. The trial had a prespecified noninferiority margin of 1.20 for the hazard ratio (HR) for the primary end point (a composite of all-cause mortality, nonfatal myocardial infarction or stroke, adjudicated by an independent blinded committee). This trial is registered with ClinicalTrials.gov, number NCT00773513.

RESULTS

In total, 2818 patients underwent randomization, received methoxy polyethylene glycol-epoetin beta or a reference agent, and were followed for a median of 3.4 years (maximum, 8.4 years). In the modified intention-to-treat analysis, a primary end point event occurred in 640 (45.4%) patients in the methoxy polyethylene glycol-epoetin beta arm, and 644 (45.7%) in the reference arm (HR 1.03; 95% confidence interval [95% CI], 0.93 to 1.15, P=0.004 for noninferiority). All-cause mortality was not different between treatment groups (HR 1.06; 95% CI, 0.94 to 1.19). Results in patient subgroups on dialysis or treated in the correction or maintenance settings were comparable to the primary analysis.

CONCLUSIONS

In patients with anemia of CKD, once-monthly methoxy polyethylene glycol-epoetin beta was noninferior to conventional, shorter-acting erythropoiesis-stimulating agents with respect to rates of major adverse cardiovascular events or all-cause mortality.

Understanding Long-Term Trajectories in Web-Based Happiness Interventions: Secondary Analysis From Two Web-Based Randomized Trials

Background

A critical issue in understanding the benefits of Web-based interventions is the lack of information on the sustainability of those benefits. Sustainability in studies is often determined using group-level analyses that might obscure our understanding of who actually sustains change. Person-centric methods might provide a deeper knowledge of whether benefits are sustained and who tends to sustain those benefits.

Objective

The aim of this study was to conduct a person-centric analysis of longitudinal outcomes, examining well-being in participants over the first 3 months following a Web-based happiness intervention. We predicted we would find distinct trajectories in people’s pattern of response over time. We also sought to identify what aspects of the intervention and the individual predicted an individual’s well-being trajectory.

Methods

Data were gathered from 2 large studies of Web-based happiness interventions: one in which participants were randomly assigned to 1 of 14 possible 1-week activities (N=912) and another wherein participants were randomly assigned to complete 0, 2, 4, or 6 weeks of activities (N=1318). We performed a variation of K-means cluster analysis on trajectories of life satisfaction (LS) and affect balance (AB). After clusters were identified, we used exploratory analyses of variance and logistic regression models to analyze groups and compare predictors of group membership.

Results

Cluster analysis produced similar cluster solutions for each sample. In both cases, participant trajectories in LS and AB fell into 1 of 4 distinct groups. These groups were as follows: those with high and static levels of happiness (n=118, or 42.8%, in Sample 1; n=306, or 52.8%, in Sample 2), those who experienced a lasting improvement (n=74, or 26.8% in Sample 1; n=104, or 18.0%, in Sample 2), those who experienced a temporary improvement but returned to baseline (n=37, or 13.4%, in Sample 1; n=82, or 14.2%, in Sample 2), and those with other trajectories (n=47, or 17.0%, in Sample 1; n=87, or 15.0% in Sample 2). The prevalence of depression symptoms predicted membership in 1 of the latter 3 groups. Higher usage and greater adherence predicted sustained rather than temporary benefits.

Conclusions

We revealed a few common patterns of change among those completing Web-based happiness interventions. A noteworthy finding was that many individuals began quite happy and maintained those levels. We failed to identify evidence that the benefit of any particular activity or group of activities was more sustainable than any others. We did find, however, that the distressed portion of participants was more likely to achieve a lasting benefit if they continued to practice, and adhere to, their assigned Web-based happiness intervention.

Adjunctive brexpiprazole in patients with major depressive disorder and anxiety symptoms: post hoc analyses of three placebo-controlled studies

OBJECTIVE

Episodes of major depressive disorder (MDD) characterized by high levels of anxiety symptoms are less likely to respond to some forms of antidepressant treatment (ADT). This report examines the effects of adjunctive brexpiprazole on depressive symptoms among patients with MDD and anxiety symptoms.

MATERIALS AND METHODS

This was a post hoc analysis of 1,171 patients from the 6-week, randomized, double-blind phases of three studies in adults with MDD and inadequate response to ADTs (NCT01360645, NCT01360632, NCT02196506). Data were pooled for brexpiprazole 2-3 mg/day and for placebo (adjunct to ADT). Montgomery-Åsberg Depression Rating Scale Total score changes were assessed in subgroups of patients with and without anxious distress (based on proxies for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria) and anxious depression (defined as a Hamilton Depression Rating Scale Anxiety/somatization factor score of ≥7). Safety was assessed by the incidence of treatment-emergent adverse events (TEAEs).

RESULTS

Benefits were seen for adjunctive brexpiprazole (compared with adjunctive placebo) in both anxiety definition subgroups. For patients with anxious distress, the least squares mean difference (95% CI) at week 6 was -3.00 (-4.29, -1.71; P<0.0001) and, for those without anxious distress, was -1.38 (-2.71, -0.05; P=0.043). For patients with anxious depression, the difference was -2.19 (-3.60, -0.78; P=0.0023), compared with -2.34 (-3.58, -1.10; P=0.0002) for those without anxious depression. The most common TEAEs among patients with anxiety symptoms receiving ADT + brexpiprazole were akathisia, headache, restlessness, somnolence, and weight increase. There were no clinically meaningful differences in the rates of these TEAEs according to the presence or absence of anxiety symptoms.

CONCLUSION

Adjunctive brexpiprazole 2-3 mg/day may be efficacious in reducing depressive symptoms, and was well tolerated, in patients with clinically relevant anxiety symptoms.

Study designs: Part 5 - interventional studies (II)

In the fifth piece of this series on research study designs, we continue the discussion on interventional studies (clinical trials), in which the investigator decides whether or not a particular participant receives the exposure (or intervention). In this article, we take a closer look at several features which are important to ensure that the findings of such a study represent the real effect of an intervention, such as allocation concealment, blinding, compliance to intervention, the use of co-interventions and participant dropout rate.

Cost Analyses of Genomic Sequencing: Lessons Learned from the MedSeq Project

OBJECTIVE

To summarize lessons learned while analyzing the costs of integrating whole genome sequencing into the care of cardiology and primary care patients in the MedSeq Project by conducting the first randomized controlled trial of whole genome sequencing in general and specialty medicine.

METHODS

Case study that describes key methodological and data challenges that were encountered or are likely to emerge in future work, describes the pros and cons of approaches considered by the study team, and summarizes the solutions that were implemented.

RESULTS

Major methodological challenges included defining whole genome sequencing, structuring an appropriate comparator, measuring downstream costs, and examining clinical outcomes. Discussions about solutions addressed conceptual and practical issues that arose because of definitions and analyses around the cost of genomic sequencing in trial-based studies.

CONCLUSIONS

The MedSeq Project provides an instructive example of how to conduct a cost analysis of whole genome sequencing that feasibly incorporates best practices while being sensitive to the varied applications and diversity of results it may produce. Findings provide guidance for researchers to consider when conducting or analyzing economic analyses of whole genome sequencing and other next-generation sequencing tests, particularly regarding costs.

Genotype-Based Recall Studies in Complex Cardiometabolic Traits

In genotype-based recall (GBR) studies, people (or their biological samples) who carry genotypes of special interest for a given hypothesis test are recalled from a larger cohort (or biobank) for more detailed investigations. There are several GBR study designs that offer a range of powerful options to elucidate (1) genotype-phenotype associations (by increasing the efficiency of genetic association studies, thereby allowing bespoke phenotyping in relatively small cohorts), (2) the effects of environmental exposures (within the Mendelian randomization framework), and (3) gene-treatment interactions (within the setting of GBR interventional trials). In this review, we overview the literature on GBR studies as applied to cardiometabolic health outcomes. We also review the GBR approaches used to date and outline new methods and study designs that might enhance the utility of GBR-focused studies. Specifically, we highlight how GBR methods have the potential to augment randomized controlled trials, providing an alternative application for the now increasingly accepted Mendelian randomization methods usually applied to large-scale population-based data sets. Further to this, we consider how functional and basic science approaches alongside GBR designs offer intellectually intriguing and potentially powerful ways to explore the implications of alterations to specific (and potentially druggable) biological pathways.

Imbalance p values for baseline covariates in randomized controlled trials: a last resort for the use of p values? A pro and contra debate

Background

Results of randomized controlled trials (RCTs) are usually accompanied by a table that compares covariates between the study groups at baseline. Sometimes, the investigators report p values for imbalanced covariates. The aim of this debate is to illustrate the pro and contra of the use of these p values in RCTs.

Pro

Low p values can be a sign of biased or fraudulent randomization and can be used as a warning sign. They can be considered as a screening tool with low positive-predictive value. Low p values should prompt us to ask for the reasons and for potential consequences, especially in combination with hints of methodological problems.

Contra

A fair randomization produces the expectation that the distribution of p values follows a flat distribution. It does not produce an expectation related to a single p value. The distribution of p values in RCTs can be influenced by the correlation among covariates, differential misclassification or differential mismeasurement of baseline covariates. Given only a small number of reported p values in the reports of RCTs, judging whether the realized p value distribution is, indeed, a flat distribution becomes difficult. If p values ≤0.005 or ≥0.995 were used as a sign of alarm, the false-positive rate would be 5.0% if randomization was done correctly, and five p values per RCT were reported.

Conclusion

Use of a low p value as a warning sign that randomization is potentially biased can be considered a vague heuristic. The authors of this debate are obviously more or less enthusiastic with this heuristic and differ in the consequences they propose.

Effects of Treatment Length and Chat-Based Counseling in a Web-Based Intervention for Cannabis Users: Randomized Factorial Trial

Background

Digital interventions show promise in reducing problematic cannabis use. However, little is known about the effect of moderators in such interventions. The therapist-guided internet intervention Quit the Shit provides 50 days of chat-based (synchronous) and time-lagged (asynchronous) counseling.

Objective

In the study, we examined whether the effectiveness of Quit the Shit is reduced by shortening the program or by removing the chat-based counseling option.

Methods

We conducted a purely Web-based randomized experimental trial using a two-factorial design (factor 1: real-time-counseling via text-chat: yes vs no; factor 2: intervention duration: 50 days vs 28 days). Participants were recruited on the Quit the Shit website. Follow-ups were conducted 3, 6, and 12 months after randomization. Primary outcome was cannabis-use days during the past 30 days using a Timeline Followback procedure. Secondary outcomes were cannabis quantity, cannabis-use events, cannabis dependency (Severity of Dependence Scale), treatment satisfaction (Client Satisfaction Questionnaire), and working alliance (Working Alliance Inventory-short revised).

Results

In total, 534 participants were included in the trial. Follow-up rates were 47.2% (252/534) after 3 months, 38.2% (204/534) after 6 months, and 25.3% (135/534) after 12 months. Provision of real-time counseling (factor 1) was not significantly associated with any cannabis-related outcome but with higher treatment satisfaction (P=.001, d=0.34) and stronger working alliance (P=.008, d=0.22). In factor 2, no significant differences were found in any outcome. The reduction of cannabis use among all study participants was strong (P<.001, d≥1.13).

Conclusions

The reduction of program length and the waiver of synchronous communication have no meaningful impact on the effectiveness of Quit the Shit. It therefore seems tenable to abbreviate the program and to offer a self-guided start into Quit the Shit. Due to its positive impact on treatment satisfaction and working alliance, chat-based counseling nevertheless should be provided in Quit the Shit.

Trial Registration

International Standard Randomized Controlled Trial Number ISRCTN99818059; http://www.isrctn.com/ISRCTN99818059 (Archived by WebCite at http://www.webcitation.org/6uVDeJjfD)

Endoscopy screening effect on stage distributions of esophageal cancer: A cluster randomized cohort study in China

Efficacy of endoscopic screening for esophageal cancer is not sufficiently definitive and lacks randomized controlled trial evidence. The present study proved short‐term screening efficacy through describing and comparing disease stage distributions of intervention and control populations. Villages from Linzhou and Cixian were cluster randomly allocated to the intervention or to the control group and the target population of 52 729 and 43 068 individuals was 40‐69 years old, respectively, and the actual enrolled numbers were 18 316 and 21 178, respectively. TNM stage information and study‐defined stage information of esophageal cases from 2012 to 2016 were collected. Stage distributions were compared between the intervention and control groups in the total target population, as well as in the subgroup populations in terms of enrolment and before or after intervention. There were a total of 199 and 141 esophageal cancer cases in the intervention and control groups, respectively. For the target population, distributions of TNM stage were borderline significant between the two groups after intervention (P = .093). However, subgroup analysis of the enrolled population during the after‐intervention period had statistical significance for both TNM and study‐defined stage. Natural TNM stage distributions were approximately 32%, 41%, 24% and 3% for stages I to IV vs 71%, 19%, 7% and 3% in the intervention population. The natural study‐defined stage distributions from early, middle to advanced stages were approximately 18%, 49% and 33% vs 59%, 33% and 8%. Early‐stage esophageal cancer cases accounted for a higher proportion after endoscopy screening, and the efficacy in the target population depends on the intervention compliance.

Extracorporeal shock wave therapy versus corticosteroid injection in the treatment of trigger finger: a randomized controlled study

The purpose of this study was to compare the efficacies of extracorporeal shock wave therapy and corticosteroid injection for the management of trigger finger. In this prospective randomized clinical trial, 40 patients with actively correctable trigger fingers were randomly assigned to extracorporeal shock wave therapy (1000 impulses and 2.1 bar) or injection groups. The effectiveness of the treatment was assessed using cure rates, a visual analogue scale, the frequency of triggering, the severity of triggering, the functional impact of triggering, and the Quick-Disabilities of the Arm, Shoulder, and Hand questionnaire at 1, 3, and 6 months after treatment. An intention-to- treat analysis was used in this study. Both groups demonstrated statistically significant improvements in all outcome measures after treatment. The intention-to-treat analyses showed no between-group differences for cure rates, pain, and functional status at follow-up. We conclude that extracorporeal shock wave therapy could be a non-invasive option for treating trigger finger, especially for those patients who wish to avoid steroid injections.

LEVEL OF EVIDENCE

Level II.

Visit-to-Visit Variability of BP and CKD Outcomes: Results from the ALLHAT

BACKGROUND AND OBJECTIVES

Increased visit-to-visit variability of BP is associated with cardiovascular disease risk. We examined the association of visit-to-visit variability of BP with renal outcomes among 21,245 participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We measured mean BP and visit-to-visit variability of BP, defined as SD, across five to seven visits occurring 6-28 months after participants were randomized to chlorthalidone, amlodipine, or lisinopril. The composite outcome included incident ESRD after assessment of SD of systolic BP or ≥50% decline in eGFR between 24 months and 48 or 72 months after randomization. We repeated the analyses using average real variability and peak value of systolic BP and for visit-to-visit variability of diastolic BP.

RESULTS

Over a mean follow-up of 3.5 years, 297 outcomes occurred. After multivariable adjustment, including baseline eGFR and mean systolic BP, the hazard ratios for the composite end point were 1.29 (95% confidence interval [95% CI], 0.75 to 2.22), 1.76 (95% CI, 1.06 to 2.91), 1.46 (95% CI, 0.88 to 2.45), and 2.05 (95% CI, 1.25 to 3.36) for the second through fifth (SD of systolic BP =6.63-8.82, 8.83-11.14, 11.15-14.56, and >14.56 mmHg, respectively) versus the first (SD of systolic BP <6.63 mmHg) quintile of SD of systolic BP, respectively (P trend =0.004). The association was similar when ESRD and a 50% decline in eGFR were analyzed separately, for other measures of visit-to-visit variability of systolic BP, and for visit-to-visit variability of diastolic BP.

CONCLUSIONS

Higher visit-to-visit variability of BP is associated with higher risk of renal outcomes independent of mean BP.

Maximum type I error rate inflation from sample size reassessment when investigators are blind to treatment labels

Consider a parallel group trial for the comparison of an experimental treatment to a control, where the second‐stage sample size may depend on the blinded primary endpoint data as well as on additional blinded data from a secondary endpoint. For the setting of normally distributed endpoints, we demonstrate that this may lead to an inflation of the type I error rate if the null hypothesis holds for the primary but not the secondary endpoint.

We derive upper bounds for the inflation of the type I error rate, both for trials that employ random allocation and for those that use block randomization. We illustrate the worst‐case sample size reassessment rule in a case study. For both randomization strategies, the maximum type I error rate increases with the effect size in the secondary endpoint and the correlation between endpoints. The maximum inflation increases with smaller block sizes if information on the block size is used in the reassessment rule. Based on our findings, we do not question the well‐established use of blinded sample size reassessment methods with nuisance parameter estimates computed from the blinded interim data of the primary endpoint. However, we demonstrate that the type I error rate control of these methods relies on the application of specific, binding, pre‐planned and fully algorithmic sample size reassessment rules and does not extend to general or unplanned sample size adjustments based on blinded data. © 2015 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Renal Scarring in the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) Trial

BACKGROUND AND OBJECTIVES

The main objectives of the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial were to evaluate the role of antimicrobial prophylaxis in the prevention of recurrent urinary tract infection (UTI) and renal scarring in children with vesicoureteral reflux (VUR). We present a comprehensive evaluation of renal scarring outcomes in RIVUR trial participants.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This multicenter, randomized, placebo-controlled trial enrolled 607 children aged 2-71 months with grade 1-4 VUR diagnosed after a first or second febrile or symptomatic UTI. Study participants received trimethoprim-sulfamethoxazole or placebo and were followed for 2 years. Renal scarring was evaluated by baseline and follow-up (99m)technetium dimercaptosuccinic acid (DMSA) renal scans that were reviewed independently by two blinded reference radiologists.

RESULTS

At the end of the study, 58 (10%) of 599 children and 63 (5%) of 1197 renal units had renal scarring. New renal scarring did not differ between the prophylaxis and placebo groups (6% versus 7%, respectively). Children with renal scarring were significantly older (median age, 26 versus 11 months; P=0.01), had a second UTI before enrollment (odds ratio [OR], 2.85; 95% confidence interval [95% CI], 1.38 to 5.92), were more likely to be Hispanic (OR, 2.22; 95% CI, 1.13 to 4.34), and had higher grades of VUR (OR, 2.79; 95% CI, 1.56 to 5.0). The proportion of new scars in renal units with grade 4 VUR was significantly higher than in units with no VUR (OR, 24.2; 95% CI, 6.4 to 91.2).

CONCLUSIONS

Significantly more renal scarring was seen in relatively older children and in those with a second episode of febrile or symptomatic UTI before randomization. Preexisting and new renal scars occurred significantly more in renal units with grade 4 VUR than in those with low-grade or no VUR. Antimicrobial prophylaxis did not decrease the risk of renal scarring.

Temporal Changes in Periprocedural Events in the Carotid Revascularization Endarterectomy Versus Stenting Trial

BACKGROUND AND PURPOSE

Post-hoc, we hypothesized that over the recruitment period of the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), increasing experience and improved patient selection with carotid stenting, and to a lesser extent, carotid endarterectomy would contribute to lower periprocedural event rates.

METHODS

Three study periods with approximately the same number of patients were defined to span recruitment. Composite and individual rates of periprocedural stroke, myocardial infarction, and death rate were calculated separately by treatment assignment (carotid stenting/carotid endarterectomy). Temporal changes in unadjusted event rates, and rates after adjustment for temporal changes in patient characteristics, were assessed.

RESULTS

For patients randomized to carotid stenting, there was no significant temporal change in the unadjusted composite rates that declined from 6.2% in the first period, to 4.9% in the second, and 4.6% in the third (P=0.28). Adjustment for patient characteristics attenuated the rates to 6.0%, 5.9%, and 5.6% (P=0.85). For carotid endarterectomy-randomized patients, both the composite and the combined stroke and death outcome decreased between periods 1 and 2 and then increased in period 3.

CONCLUSIONS

The hypothesized temporal reduction of stroke+death events for carotid stenting-treated patients was not observed. Further adjustment for changes in patient characteristics between periods, including the addition of asymptomatic patients and a >50% decrease in proportion of octogenarians enrolled, resulted in practically identical rates.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

Do current clinical trials meet society's needs?: a critical review of recent evidence

This paper describes some important controversies regarding the current state of clinical trials research in cardiology. Topics covered include the inadequacy of trial research on medical devices, problems with industry-sponsored trials, the lack of head-to-head trials of new effective treatments, the need for wiser handling of drug safety issues, the credibility (or lack thereof) of trial reports in medical journals, problems with globalization of trials, the role of personalized (stratified) medicine in trials, the need for new trials of old drugs, the need for trials of treatment withdrawal, the importance of pragmatic trials of treatment strategies, and the limitations of observational comparative effectiveness studies. All issues are illustrated by recent topical trials in cardiology. Overall, we explore the extent to which clinical trials, as currently practiced, are successful in meeting society's expectations.

Randomized controlled trial on the efficacy of new alcohol-free chlorhexidine mouthrinses after 8 weeks

OBJECTIVES

To evaluate the efficacy of two alcohol-free antimicrobial mouthrinses in reducing plaque and gingivitis compared to an alcohol-containing rinse and toothbrushing alone.

METHODS

One hundred and sixty healthy volunteers were enrolled in the randomized controlled trial. Participants were randomly and equally assigned to four groups: (i) toothbrushing + rinsing (0.06% CHX + 0.025% NaF, alcohol-containing rinse, positive control); (ii) toothbrushing + rinsing (0.06% CHX + 0.025% NaF, alcohol-free experimental rinse); (iii) toothbrushing + rinsing (0.06% CHX + 0.03% CPC + 0.025% NaF, alcohol-free experimental rinse); (iv) toothbrushing alone (negative control). At baseline, Quigley-Hein plaque index (QHI), modified proximal plaque index (MPPI), and papillary bleeding index (PBI) were recorded. All subjects brushed their teeth as usual during the study. Additionally, groups 1-3 rinsed twice daily. Eight weeks after baseline, indices were recorded again. anova with Bonferroni adjustment served for statistical analysis.

RESULTS

One hundred and fifty-five participants were included into final analysis (i: n = 39, 2: n = 39, 3: n = 37, 4: n = 40). Experimental rinses (ii, iii) reduced QHI and MPPI to a higher extent than the negative control (iv), whereas no significant difference to the positive control was found. QHI: (i) 36.6%, (ii) 32.3%, (iii) 36.8%, (iv) 21.6%; MPPI: (i) 11.9%, (ii) 12.2%, (iii) 13.6%, (iv) 3.5%. For PBI, no statistically significant difference was found between groups: (i) 80.2%, (ii) 77.8%, (iii) 76.5% and (iv) 78.8%.

CONCLUSIONS

With respect to QHI and MPPI, toothbrushing in combination with any rinse was more effective than toothbrushing alone. No statistically significant differences were found between the alcohol-free and the alcohol-containing control rinses.

Bone graft substitutes for the treatment of traumatic fractures of the extremities

HEALTH POLITICAL AND SCIENTIFIC BACKGROUND: Bone graft substitutes are increasingly being used as supplements to standard care or as alternative to bone grafts in the treatment of traumatic fractures.

RESEARCH QUESTIONS

The efficacy and cost-effectiveness of bone graft substitutes for the treatment of traumatic fractures as well as the ethical, social and legal implications of their use are the main research questions addressed.

METHODS

A systematic literature search was conducted in electronic medical databases (MEDLINE, EMBASE etc.) in December 2009. Randomised controlled trials (RCT), where applicable also containing relevant health economic evaluations and publications addressing the ethical, social and legal aspects of using bone graft substitutes for fracture treatment were included in the analysis. After assessment of study quality the information synthesis of the medical data was performed using metaanalysis, the synthesis of the health economic data was performed descriptively.

RESULTS

14 RCT were included in the medical analysis, and two in the heath economic evaluation. No relevant publications on the ethical, social and legal implications of the bone graft substitute use were found. In the RCT on fracture treatment with bone morphogenetic protein-2 (BMP-2) versus standard care without bone grafting (RCT with an elevated high risk of bias) there was a significant difference in favour of BMP-2 for several outcome measures. The RCT of calcium phosphate (CaP) cement and bone marrow-based composite materials versus autogenous bone grafts (RCT with a high risk of bias) revealed significant differences in favour of bone graft substitutes for some outcome measures. Regarding the other bone graft substitutes, almost all comparisons demonstrated no significant difference. The use of BMP-2 in addition to standard care without bone grafting led in the study to increased treatment costs considering all patients with traumatic open fractures. However, cost savings through the additional use of BMP-2 were calculated in a patient subgroup with high-grade open fractures (Gustilo-Anderson grade IIIB). Cost-effectiveness for BMP-2 versus standard care with autologous bone grafts as well as for other bone graft substitutes in fracture treatment has not been determined yet.

DISCUSSION

Although there were some significant differences in favour of BMP-2, due to the overall poor quality of the studies the evidence can only be interpreted as suggestive for efficacy. In the case of CaP cements and bone marrow-based bone substitute materials, the evidence is only weakly suggestive for efficacy. From an overall economic perspective, the transferability of the results of the health economic evaluations to the current situation in Germany is limited.

CONCLUSIONS

The current evidence is insufficient to evaluate entirely the use of different bone graft substitutes for fracture treatment. From a medical point of view, BMP-2 is a viable alternative for treatment of open fractures of the tibia, especially in cases where bone grafting is not possible. Autologous bone grafting is preferable comparing to the use of OP-1. Possible advantages of CaP cements and composites containing bone marrow over autogenous bone grafting should be taken into account in clinical decision making. The use of the hydroxyapatite material and allograft bone chips compared to autologous bone grafts cannot be recommended. From a health economic perspective, the use of BMP-2 in addition to standard care without bone grafting is recommended as cost-saving in patients with high-grade open fractures (Gustilo-Anderson grade IIIB). Based on the current evidence no further recommendations can be made regarding the use of bone graft substitutes for the treatment of fractures. To avoid legal implications, use of bone graft substitutes outside their approved indications should be avoided.

The effectiveness of interventions in workplace health promotion as to maintain the working capacity of health care personal

Background

The increasing proportion of elderly people with respective care requirements and within the total population stands against aging personnel and staff reduction in the field of health care where employees are exposed to high load factors. Health promotion interventions may be a possibility to improve work situations and behavior.

Methods

A systematic literature search is conducted in 32 databases limited to English and German publications since 1990. Moreover, internet-searches are performed and the reference lists of identified articles are scanned. The selection of literature was done by two reviewers independently according to inclusion and exclusion criteria. Data extraction and tables of evidence are verified by a second expert just like the assessment of risk of bias by means of the Cochrane Collaboration’s tool.

Results

We identified eleven intervention studies and two systematic reviews. There were three randomized controlled trials (RCT) and one controlled trial without randomization (CCT) on the improvement of physical health, four RCT and two CCT on the improvement of psychological health and one RCT on both. Study duration ranged from four weeks to two years and the number of participants included from 20 to 345, with a median of 56. Interventions and populations were predominantly heterogeneous. In three studies intervention for the improvement of physical health resulted in less complaints and increased strength and flexibility with statistically significant differences between groups. Regarding psychological health interventions lead to significantly decreased intake of analgesics, better stress management, coping with workload, communication skills and advanced training.

Discussion

Taking into consideration the small to very small sample sizes, other methodological flaws like a high potential of bias and poor quality of reporting the validity of the results has to be considered as limited. Due to the heterogeneity of health interventions, study populations with differing job specializations and different lengths of study durations and follow-up periods, the comparison of results would not make sense.

Conclusions

Further research is necessary with larger sample sizes, with a sufficient study duration and follow-up, with a lower risk of bias, by considering of relevant quality criteria and with better reporting in publications.

Individual health services

BACKGROUND

The German statutory health insurance (GKV) reimburses all health care services that are deemed sufficient, appropriate, and efficient. According to the German Medical Association (BÄK), individual health services (IGeL) are services that are not under liability of the GKV, medically necessary or recommendable or at least justifiable. They have to be explicitly requested by the patient and have to be paid out of pocket.

RESEARCH QUESTIONS

The following questions regarding IGeL in the outpatient health care of GKV insurants are addressed in the present report: What is the empirical evidence regarding offers, utilization, practice, acceptance, and the relation between physician and patient, as well as the economic relevance of IGeL?What ethical, social, and legal aspects are related to IGeL? FOR TWO OF THE MOST COMMON IGEL, THE SCREENING FOR GLAUCOMA AND THE SCREENING FOR OVARIAN AND ENDOMETRIAL CANCER BY VAGINAL ULTRASOUND (VUS), THE FOLLOWING QUESTIONS ARE ADDRESSED: What is the evidence for the clinical effectiveness?Are there sub-populations for whom screening might be beneficial?

METHODS

The evaluation is divided into two parts. For the first part a systematic literature review of primary studies and publications concerning ethical, social and legal aspects is performed. In the second part, rapid assessments of the clinical effectiveness for the two examples, glaucoma and VUS screening, are prepared. Therefore, in a first step, HTA-reports and systematic reviews are searched, followed by a search for original studies published after the end of the research period of the most recent HTA-report included.

RESULTS

29 studies were included for the first question. Between 19 and 53% of GKV members receive IGeL offers, of which three-quarters are realised. 16 to 19% of the insurants ask actively for IGeL. Intraocular tension measurement is the most common single IGeL service, accounting for up to 40% of the offers. It is followed by ultrasound assessments with up to 25% of the offers. Cancer screening and blood or laboratory services are also frequent and represent a major proportion of the demand. The ethical, social, and legal aspects discussed in the context of IGeL concern eight subject areas: autonomous patient decisions versus obtrusion,commercialization of medicine, duty of patient information, benefit, evidence, and (quality) control, role and relation of physicians and patients,relation to the GKV, social inequality,formally correct performance. For glaucoma screening, no randomized controlled trial (RCT) is identified that shows a patient relevant benefit. For VUS three RCT are included. However, they do not yet present mortality data concerning screened and non-screened persons. VUS screening shows a high degree of over-diagnosis in turn leading to invasive interventions. To diagnose one invasive carcinoma, 30 to 35 surgical procedures are necessary.

CONCLUSION

IGeL are a relevant factor in the German statutory health care system. To provide more transparency, the requests for evidence-based and independent patient information should be considered. Whether official positive and negative-lists could be an appropriate instrument to give guidance to patients and physicians, should be examined. Generally, IGeL must be seen in the broader context of the discussions about the future design and development of the German health care system.

Prevention of alcohol misuse among children, youths and young adults

BACKGROUND

Despite many activities to prevent risky alcohol consumption among adolescents and young adults there is an increase of alcohol intoxications in the group of ten to twenty year old juveniles.

OBJECTIVES

This report gives an overview about the recent literature as well as the German federal prevention system regarding activities concerning behavioral and policy prevention of risky alcohol consumption among children, adolescents and young adults. Furthermore, effective components of prevention activities are identified and the efficiency and efficacy of ongoing prevention programs is evaluated.

METHODS

A systematic literature review is done in 34 databases using Bool'sche combinations of the key words alcohol, prevention, treatment, children, adolescents and young adults.

RESULTS

401 studies were found and 59 studies were selected for the health technology assessment (HTA). Most of the studies are done in USA, nine in Germany. A family strengthening program, personalized computer based intervention at schools, colleges and universities, brief motivational interventions and policy elements like increase of prices and taxes proved effective.

DISCUSSION

Among the 59 studies there are three meta-analyses, 15 reviews, 17 randomized controlled trials (RCT) and 18 cohort studies. Despite the overall high quality of the study design, many of them have methodological weaknesses (missing randomization, missing or too short follow-ups, not clearly defined measurement parameters). The transferability of US-results to the German context is problematic. Only a few prevention activities reach a sustainable reduction of frequency and/or amount of alcohol consumption.

CONCLUSION

The HTA-report shows the need to develop specific and target group focused prevention activities for the German situation. Essential for that is the definition of target goals (reduction of consumption, change of behaviour) as well as the definition and empirical validation of risky alcohol consumption. The efficacy of prevention activities should be proven before they are launched. At present activities for the reduction or prevention of risky alcohol consumption are not sufficiently evaluated in Germany concerning their sustainable efficacy.

Over-, under- and misuse of pain treatment in Germany

BACKGROUND

The HTA-report (Health Technology Assessment) deals with over- and undertreatment of pain therapy. Especially in Germany chronic pain is a common reason for the loss of working hours and early retirement. In addition to a reduction in quality of life for the affected persons, chronic pain is therefore also an enormous economic burden for society.

OBJECTIVES

Which diseases are in particular relevant regarding pain therapy?What is the social-medical care situation regarding pain facilities in Germany?What is the social-medical care situation in pain therapy when comparing on international level?Which effects, costs or cost-effects can be seen on the micro-, meso- and macro level with regard to pain therapy?Among which social-medical services in pain therapy is there is an over- or undertreatment with regard to the micro-, meso- and macro level?Which medical and organisational aspects that have an effect on the costs and/or cost-effectiveness have to be particularly taken into account with regard to pain treatment/chronic pain?What is the influence of the individual patient's needs (micro level) in different situations of pain (e. g. palliative situation) on the meso- and macro level?Which social-medical and ethical aspects for an adequate treatment of chronic pain on each level have to be specially taken into account?Is the consideration of these aspects appropriate to avoid over- or undertreatment?Are juridical questions included in every day care of chronic pain patients, mainly in palliative care?On which level can appropriate interventions prevent over- or undertreatment?

METHODS

A systematic literature research is done in 35 databases. In the HTA, reviews, epidemiological and clinical studies and economic evaluations are included which report about pain therapy and in particular palliative care in the years 2005 till 2010.

RESULTS

47 studies meet the inclusion criteria. An undertreatment of acupuncture, over- and misuse with regard to opiate prescription and an overuse regarding unspecific chest pain and chronic low back pain (LBP) can be observed. The results show the benefit and the cost-effectiveness of interdisciplinary as well as multi-professional approaches, multimodal pain therapy and cross-sectoral integrated medical care. Only rough values can be determined about the care situation regarding the supply of pain therapeutic and palliative medical facilities as the data are completely insufficient.

DISCUSSION

Due to the broad research question the HTA-report contains inevitably different outcomes and study designs which partially differ qualitatively very strong from each other. In the field of palliative care hospices for in-patients and palliative wards as well as hospices for out-patients are becoming more and more important. Palliative care is a basic right of all terminally ill persons.

CONCLUSION

Despite the relatively high number of studies in Germany the HTA-report shows a massive lack in health care research. Based on the studies a further expansion of out-patient pain and palliative care is recommended. Further training for all involved professional groups must be improved. An independent empirical analysis is necessary to determine over or undertreatment in pain care.

Randomisation to protect against selection bias in healthcare trials

BACKGROUND

Randomised trials use the play of chance to assign participants to comparison groups. The unpredictability of the process, if not subverted, should prevent systematic differences between comparison groups (selection bias). Differences due to chance will still occur and these are minimised by randomising a sufficiently large number of people.

OBJECTIVES

To assess the effects of randomisation and concealment of allocation on the results of healthcare studies.

SEARCH STRATEGY

We searched the Cochrane Methodology Register, MEDLINE, SciSearch and reference lists up to September 2009. In addition, we screened articles citing included studies (ISI Science Citation Index) and papers related to included studies (PubMed).

SELECTION CRITERIA

Eligible study designs were cohorts of studies, systematic reviews or meta-analyses of healthcare interventions that compared random allocation versus non-random allocation or adequate versus inadequate/unclear concealment of allocation in randomised trials. Outcomes of interest were the magnitude and direction of estimates of effect and imbalances in prognostic factors.

DATA COLLECTION AND ANALYSIS

We retrieved and assessed studies that appeared to meet the inclusion criteria independently. At least two review authors independently appraised methodological quality and extracted information. We prepared tabular summaries of the results for each comparison and assessed the results across studies qualitatively to identify common trends or discrepancies.

MAIN RESULTS

A total of 18 studies (systematic reviews or meta-analyses) met our inclusion criteria. Ten compared random allocation versus non-random allocation and nine compared adequate versus inadequate or unclear concealment of allocation within controlled trials. All studies were at high risk of bias.For the comparison of randomised versus non-randomised studies, four comparisons yielded inconclusive results (differed between outcomes or different modes of analysis); three comparisons showed similar results for random and non-random allocation; two comparisons had larger estimates of effect in non-randomised studies than in randomised trials; and two comparisons had larger estimates of effect in randomised than in non-randomised studies.Five studies found larger estimates of effect in trials with inadequate concealment of allocation than in trials with adequate concealment. The four other studies did not find statistically significant differences.

AUTHORS' CONCLUSIONS

The results of randomised and non-randomised studies sometimes differed. In some instances non-randomised studies yielded larger estimates of effect and in other instances randomised trials yielded larger estimates of effect. The results of controlled trials with adequate and inadequate/unclear concealment of allocation sometimes differed. When differences occurred, most often trials with inadequate or unclear allocation concealment yielded larger estimates of effects relative to controlled trials with adequate allocation concealment. However, it is not generally possible to predict the magnitude, or even the direction, of possible selection biases and consequent distortions of treatment effects from studies with non-random allocation or controlled trials with inadequate or unclear allocation concealment.

Informative value of Patient Reported Outcomes (PRO) in Health Technology Assessment (HTA)

Background

“Patient-Reported Outcome” (PRO) is used as an umbrella term for different concepts for measuring subjectively perceived health status e. g. as treatment effects. Their common characteristic is, that the appraisal of the health status is reported by the patient himself. In order to describe the informative value of PRO in Health Technology Assessment (HTA) first an overview of concepts, classifications and methods of measurement is given. The overview is complemented by an empirical analysis of clinical trials and HTA-reports on rheumatoid arthritis and breast cancer in order to report on type, frequency and consequences of PRO used in these documents.

Methods

For both issues systematic reviews of the literature have been performed. The search for methodological literature covers the publication period from 1990 to 2009, the search for clinical trials of rheumatoid arthritis and breast cancer covers the period 2005 to 2009. Both searches were performed in the medical databases of the German Institute of Medical Documentation and Information (DIMDI). The search for HTA-reports and methodological papers of HTA-agencies was performed in the CRD-Databases (CRD = Centre for Reviews and Dissemination) and by handsearching the websites of INAHTA member agencies (INAHTA = International Network of Agencies for Health Technology Assessment). For all issues specific inclusion and exclusion criteria were defined. The methodological quality of randomized controlled trials (RCT) was assessed by a modified version of the Cochrane Risk of Bias Tool. For the methodological part information extraction from the literature is structured by the report’s chapters, for the empirical part data extraction sheets were constructed. All information is summarized in a qualitative manner.

Results

Concerning the methodological issues the literature search retrieved 158 documents (87 documents related to definition or classification, 125 documents related to operationalisation of PRO). For the empirical analyses 225 RCT (rheumatoid arthritis: 77; breast cancer: 148) and 40 HTA-reports and method papers were found.

The analysis of the methodological literature confirms the role of PRO as an umbrella term for a variety of different concepts. The newest classification system facilitates the description of PRO measures by construct, target population and the method of measurement. Steps of operationalisation involve defining a conceptual framework, instrument development, exploration of measurement properties or, possibly, the modification of existing instruments.

Seven out of 59 RCT analysing the effects of antibody therapy for rheumatoid arthritis define PRO as the primary endpoint, 38 trials utilize composite measures (ACR, DAS) and ten trials report clinical or radiological parameters as the primary endpoint. Six out of 123 chemotherapy trials for breast cancer define PRO as the primary endpoint, while 98 trials report clinical endpoints (survival, tumour response, progression) in their primary analyses. Discrepancies in the number of trials result from inaccurate specifications of endpoints in the publications. This distribution is reflected in the HTA-reports: while almost all reports on rheumatoid arthritis refer to PRO, this is only the case in about half of the reports on breast cancer.

Conclusions

As definition and classification of PRO are concerned, coherent concepts are found in the literature. Their operationalisation and implementation must be guided by scientific principles. The type and frequency of PRO used in clinical trials largely depend on the disease analysed. The HTA-community seems to pursue the utilization of PRO proactively – in case of missing data the need for further research is stated.

The importance of growth factors for the treatment of chronic wounds in the case of diabetic foot ulcers

INTRODUCTION

Ulcers as a result of diabetes mellitus are a serious problem with an enormous impact on the overall global disease burden due to the increasing prevalence of diabetes. Because of long hospital stays, rehabilitation, often required home care and the use of social services diabetic foot complications are costly. Therapy with growth factors could be an effective and innovative add-on to standard wound care.

RESEARCH QUESTIONS

What is the benefit of therapies with growth factors alone or in combination with other technologies in the treatment of diabetic foot ulcer assessed regarding medical, economical, social, ethical and juridical aspects?

METHODS

We systematically searched relevant databases limited to English and German language and publications since 1990. Cost values were adjusted to the price level of 2008 and converted into Euro. A review and an assessment of the quality of publications were conducted following approved methodical standards conforming to evidence-based medicine and health economics.

RESULTS

We identified 25 studies (14 randomized controlled trials (RCT), nine cost-effectiveness analyses, two meta-analyses). The RCT compared an add-on therapy to standard wound care with standard wound care/placebo alone or extracellular wound matrix: in six studies becaplermin, in two rhEGF, in one bFGF, and in five studies the metabolically active skin grafts Dermagraft and Apligraf. The study duration ranged from twelve to 20 weeks and the study population included between 17 to 382 patients, average 130 patients. The treatment with becaplermin, rhEGF and skin implants Dermagraft and Apligraf showed in eight out of 13 studies an advantage concerning complete wound closure and the time to complete wound healing. Evidence for a benefit of treatment with bFGF could not be found. In four out of 14 studies the proportion of adverse events was 30% per study group with no difference between the treatment groups. The methodological quality of the studies was affected by significant deficiencies. The results showed becaplermin being cost-effective whereas no obvious statement can be made regarding Dermagraft and Apligraf because of diverging cost bases and incremental cost-effectiveness ratios.

DISCUSSION

Differences in standard wound care are complicating the comparison of study results. Taking into consideration the small to very small sample sizes and other methodological flaws with high potential of bias, the validity of the results with regard to effectiveness and cost-effectiveness has to be considered limited. The duration of treatment and follow-up examinations is not long enough to assess the sustainability of the intervention and the surveillance of ulcer recurrences or treatment related adverse events like the development of malignancy.

CONCLUSIONS

There are indications of an advantage for the add-on therapy with growth factors in diabetic foot ulcers concerning complete wound closure and the time to complete wound healing. Further more studies of high methodological quality with adequate sample sizes and sufficient follow-up periods are necessary also investigating patient-relevant parameters like the health-related quality of life, the acceptance and tolerance of the intervention in addition to clinical outcomes.

Increased hypothalamic-pituitary-adrenal axis activity and hepatic insulin resistance in low-birth-weight rats

Individuals born with a low birth weight (LBW) have an increased prevalence of type 2 diabetes, but the mechanisms responsible for this association are unknown. Given the important role of insulin resistance in the pathogenesis of type 2 diabetes, we examined insulin sensitivity in a rat model of LBW due to intrauterine fetal stress. During the last 7 days of gestation, rat dams were treated with dexamethasone and insulin sensitivity was assessed in the LBW offspring by a hyperinsulinemic euglycemic clamp. The LBW group had liver-specific insulin resistance associated with increased levels of PEPCK expression. These changes were associated with pituitary hyperplasia of the ACTH-secreting cells, increased morning plasma ACTH concentrations, elevated corticosterone secretion during restraint stress, and an approximately 70% increase in 24-h urine corticosterone excretion. These data support the hypothesis that prenatal stress can result in chronic hyperactivity of the hypothalamic-pituitary-adrenal axis, resulting in increased plasma corticosterone concentrations, upregulation of hepatic gluconeogenesis, and hepatic insulin resistance.

Polyethylene glycol, unique among laxatives, suppresses aberrant crypt foci, by elimination of cells

OBJECTIVE

Polyethylene glycol (PEG), an osmotic laxative, is a potent inhibitor of colon cancer in rats. In a search for the underling mechanisms, the hypothesis that fecal bulking and moisture decrease colon carcinogenesis was tested. We also investigated the PEG effects on crypt cells in vivo.

MATERIAL AND METHODS

Fischer 344 rats (n=272) were injected with the colon carcinogen, azoxymethane. They were then randomized to a standard AIN76 diet containing one of 19 laxative agents (5% w/w in most cases): PEG 8000 and other PEG-like compounds, carboxymethylcellulose, polyvinylpyrrolidone, sodium polyacrylate, calcium polycarbophil, karaya gum, psyllium, mannitol, sorbitol, lactulose, propylene glycol, magnesium hydroxide, sodium phosphate, bisacodyl, docusate, and paraffin oil. Aberrant crypt foci (ACF) and fecal values were measured blindly after a 30-day treatment regimen. Proliferation, apoptosis, and the removal of cells from crypts were studied in control and PEG-fed rats using various methods, including TUNEL and fluorescein dextran labeling.

RESULTS

PEG 8000 reduced the number of ACF 9-fold in rats (p<0.001). The other PEGs and magnesium hydroxide modestly suppressed ACF, but not the other laxatives. ACF number did not correlate with fecal weight or moisture. PEG doubled the apoptotic bodies per crypt (p<0.05), increased proliferation by 25-50% (p<0.05) and strikingly increased (>40-fold) a fecal marker of epitheliolysis in the gut (p<0.001). PEG normalized the percentage of fluorescein dextran labeled cells on the top of ACF (p<0.001).

CONCLUSIONS

Among laxatives, only PEG afforded potent chemoprevention. PEG protection was not due to increased fecal bulking, but in all likelihood to the elimination of cells from precancerous lesions.

Endogenous N-nitroso compounds, and their precursors, present in bacon, do not initiate or promote aberrant crypt foci in the colon of rats

Processed meat intake is associated with increased risk of colorectal cancer. This association may be explained by the endogenous formation of N-nitroso compounds (NOC). The hypothesis that meat intake can increase fecal NOC levels and colon carcinogenesis was tested in 175 Fischer 344 rats. Initiation was assessed by the number of aberrant crypt foci (ACF) in the colon of rats 45 days after the start of a high-fat bacon-based diet. Promotion was assessed by the multiplicity of ACF (crypts per ACF) in rats given experimental diets for 100 days starting 7 days after an azoxymethane injection. Three promotion studies were done, each in 5 groups of 10 rats, whose diets contained 7%, 14%, or 28% fat. Tested meats were bacon, pork, chicken, and beef. Fecal and dietary NOC were assayed by thermal energy analysis. Results show that feces from rats fed bacon-based diets contained 10-20 times more NOC than feces from control rats fed a casein-based diet (all p < 0.0001 in 4 studies). In bacon-fed rats, the amount of NOC input (diet) and output (feces) was similar. Rats fed a diet based on beef, pork, or chicken meat had less fecal NOC than controls (most p < 0.01). No ACF were detected in the colon of bacon-fed uninitiated rats. After azoxymethane injection, unprocessed but cooked meat-based diets did not change the number of ACF or the ACF multiplicity compared with control rats. In contrast, the bacon-based diet consistently reduced the number of large ACF per rat and the ACF multiplicity in the three promotion studies by 12%, 17%, and 20% (all p < 0.01). Results suggest that NOC from dietary bacon would not enhance colon carcinogenesis in rats.

Effect of meat (beef, chicken, and bacon) on rat colon carcinogenesis

High intake of red meat or processed meat is associated with increased risk of colon cancer. In contrast, consumption of white meat (chicken) is not associated with risk and might even reduce the occurrence of colorectal cancer. We speculated that a diet containing beef or bacon would increase and a diet containing chicken would decrease colon carcinogenesis in rats. One hundred female Fischer 344 rats were given a single injection of azoxymethane (20 mg/kg i.p.), then randomized to 10 different AIN-76-based diets. Five diets were adjusted to 14% fat and 23% protein and five other diets to 28% fat and 40% protein. Fat and protein were supplied by 1) lard and casein, 2) olive oil and casein, 3) beef, 4) chicken with skin, and 5) bacon. Meat diets contained 30% or 60% freeze-dried fried meat. The diets were given ad libitum for 100 days, then colon tumor promotion was assessed by the multiplicity of aberrant crypt foci [number of crypts per aberrant crypt focus (ACF)]. The ACF multiplicity was nearly the same in all groups, except bacon-fed rats, with no effect of fat and protein level or source (p = 0.7 between 8 groups by analysis of variance). In contrast, compared with lard- and casein-fed controls, the ACF multiplicity was reduced by 12% in rats fed a diet with 30% bacon and by 20% in rats fed a diet with 60% bacon (p < 0.001). The water intake was higher in bacon-fed rats than in controls (p < 0.0001). The concentrations of iron and bile acids in fecal water and total fatty acids in feces changed with diet, but there was no correlation between these concentrations and the ACF multiplicity. Thus the hypothesis that colonic iron, bile acids, or total fatty acids can promote colon tumors is not supported by this study. The results suggest that, in rats, beef does not promote the growth of ACF and chicken does not protect against colon carcinogenesis. A bacon-based diet appears to protect against carcinogenesis, perhaps because bacon contains 5% NaCl and increased the rats' water intake.