Accuracy of syndrome definitions based on diagnoses in physician claims

Background

Community clinics offer potential for timelier outbreak detection and monitoring than emergency departments. However, the accuracy of syndrome definitions used in surveillance has never been evaluated in community settings. This study's objective was to assess the accuracy of syndrome definitions based on diagnostic codes in physician claims for identifying 5 syndromes (fever, gastrointestinal, neurological, rash, and respiratory including influenza-like illness) in community clinics.

Methods

We selected a random sample of 3,600 community-based primary care physicians who practiced in the fee-for-service system in the province of Quebec, Canada in 2005-2007. We randomly selected 10 visits per physician from their claims, stratifying on syndrome type and presence, diagnosis, and month. Double-blinded chart reviews were conducted by telephone with consenting physicians to obtain information on patient diagnoses for each sampled visit. The sensitivity, specificity, and positive predictive value (PPV) of physician claims were estimated by comparison to chart review.

Results

1,098 (30.5%) physicians completed the chart review. A chart entry on the date of the corresponding claim was found for 10,529 (95.9%) visits. The sensitivity of syndrome definitions based on diagnostic codes in physician claims was low, ranging from 0.11 (fever) to 0.44 (respiratory), the specificity was high, and the PPV was moderate to high, ranging from 0.59 (fever) to 0.85 (respiratory). We found that rarely used diagnostic codes had a higher probability of being false-positives, and that more commonly used diagnostic codes had a higher PPV.

Conclusions

Future research should identify physician, patient, and encounter characteristics associated with the accuracy of diagnostic codes in physician claims. This would enable public health to improve syndromic surveillance, either by focusing on physician claims whose diagnostic code is more likely to be accurate, or by using all physician claims and weighing each according to the likelihood that its diagnostic code is accurate.

The clinical effectiveness of negative pressure wound therapy: a systematic review

OBJECTIVE

To estimate the efficacy of negative pressure wound therapy (NPWT), on the basis of a systematic review of reported randomised controlled trials (RCTs).

METHOD

A systematic literature search for relevant RCTs was carried out. The credibility of the outcome of each study was evaluated using a specially constructed instrument.

RESULTS

We identified 17 RCTs, of which five had not been included in previous reviews or health technology assessments. For diabetic foot ulcers (seven RCTs), there was consistent evidence of the benefit of NPWT compared with control treatments. For pressure ulcers (three RCTs), results were conflicting. In trials involving mixed wounds (five RCTs), evidence was encouraging but of inadequate quality. Significant complications were not increased.

CONCLUSION

There is now sufficient evidence to show that NPWT is safe, and will accelerate healing, to justify its use in the treatment of diabetes-associated chronic leg wounds. There is also evidence, though of poor quality, to suggest that healing of other wounds may also be accelerated.

Gait speed as an incremental predictor of mortality and major morbidity in elderly patients undergoing cardiac surgery

OBJECTIVES

The purpose of this study was to test the value of gait speed, a clinical marker for frailty, to improve the prediction of mortality and major morbidity in elderly patients undergoing cardiac surgery.

BACKGROUND

It is increasingly difficult to predict the elderly patient's risk posed by cardiac surgery because existing risk assessment tools are incomplete.

METHODS

A multicenter prospective cohort of elderly patients undergoing cardiac surgery was assembled at 4 tertiary care hospitals between 2008 and 2009. Patients were eligible if they were 70 years of age or older and were scheduled for coronary artery bypass and/or valve replacement or repair. The primary predictor was slow gait speed, defined as a time taken to walk 5 m of ≥ 6 s. The primary end point was a composite of in-hospital post-operative mortality or major morbidity.

RESULTS

The cohort consisted of 131 patients with a mean age of 75.8 ± 4.4 years; 34% were female patients. Sixty patients (46%) were classified as slow walkers before cardiac surgery. Slow walkers were more likely to be female (43% vs. 25%, p = 0.03) and diabetic (50% vs. 28%, p = 0.01). Thirty patients (23%) experienced the primary composite end point of mortality or major morbidity after cardiac surgery. Slow gait speed was an independent predictor of the composite end point after adjusting for the Society of Thoracic Surgeons risk score (odds ratio: 3.05; 95% confidence interval: 1.23 to 7.54).

CONCLUSIONS

Gait speed is a simple and effective test that may identify a subset of vulnerable elderly patients at incrementally higher risk of mortality and major morbidity after cardiac surgery.

Omega-3 fatty acids in high-risk cardiovascular patients: a meta-analysis of randomized controlled trials

BACKGROUND

Multiple randomized controlled trials (RCTs) have examined the cardiovascular effects of omega-3 fatty acids and have provided unexplained conflicting results. A meta-analysis of these RCTs to estimate efficacy and safety and potential sources of heterogeneity may be helpful.

METHODS

The Cochrane library, MEDLINE, and EMBASE were systematically searched to identify all interventional trials of omega-3 fatty acids compared to placebo or usual diet in high-risk cardiovascular patients. The primary outcome was all-cause mortality and secondary outcomes were coronary restenosis following percutaneous coronary intervention and safety. Meta-analyses were carried out using Bayesian random-effects models, and heterogeneity was examined using meta-regression.

RESULTS

A total of 29 RCTs (n = 35,144) met our inclusion criteria, with 25 reporting mortality and 14 reporting restenosis. Omega-3 fatty acids were not associated with a statistically significant decreased mortality (relative risk [RR] = 0.88, 95% Credible Interval [CrI] = 0.64, 1.03) or with restenosis prevention (RR = 0.89, 95% CrI = 0.72, 1.06), though the probability of some benefit remains high (0.93 and 0.90, respectively). However in meta-regressions, there was a >90% probability that larger studies and those with longer follow-up were associated with smaller benefits. No serious safety issues were identified.

CONCLUSIONS

Although not reaching conventional statistical significance, the evidence to date suggests that omega-3 fatty acids may result in a modest reduction in mortality and restenosis. However, caution must be exercised in interpreting these benefits as results were attenuated in higher quality studies, suggesting that bias may be at least partially responsible. Additional high quality studies are required to clarify the role of omega-3 fatty acid supplementation for the secondary prevention of cardiovascular disease.

Tuberculosis infection among young nursing trainees in South India

Background

Among healthcare workers in developing countries, nurses spend a large amount of time in direct contact with tuberculosis (TB) patients, and are at high risk for acquisition of TB infection and disease. To better understand the epidemiology of nosocomial TB among nurses, we recruited a cohort of young nursing trainees at Christian Medical College, a large, tertiary medical school hospital in Southern India.

Methodology/Principal Findings

Among 535 nursing students enrolled in 2007, 468 gave consent to participate, and 436 underwent two-step tuberculin skin testing (TST). A majority (95%) were females, and almost 80% were under 22 years of age. Detailed TB exposure information was obtained using interviews and clinical log books. Prevalence of latent TB infection (LTBI) was estimated using Bayesian latent class analyses (LCA). Logistic regression analyses were done to determine the association between LTBI prevalence and TB exposure and risk factors. 219 of 436 students (50.2%, 95% CI: 45.4–55.0) were TST positive using the 10 mm or greater cut-off. Based on the LCA, the prevalence of LTBI was 47.8% (95% credible interval 17.8% to 65.6%). In the multivariate analysis, TST positivity was strongly associated with time spent in health care, after adjusting for age at entry into healthcare.

Conclusions

Our study showed a high prevalence of LTBI even in young nursing trainees. With the recent TB infection control (TBIC) policy guidance from the World Health Organization as the reference, Indian healthcare providers and the Indian Revised National TB Control Programme will need to implement TBIC interventions, and enhance capacity for TBIC at the country level. Young trainees and nurses, in particular, will need to be targeted for TBIC interventions.

Hand hygiene with soap and water is superior to alcohol rub and antiseptic wipes for removal of Clostridium difficile

OBJECTIVE

To evaluate common hand hygiene methods for efficacy in removing Clostridium difficile.

DESIGN

Randomized crossover comparison among 10 volunteers with hands experimentally contaminated by nontoxigenic C. difficile.

METHODS

Interventions included warm water with plain soap, cold water with plain soap, warm water with antibacterial soap, antiseptic hand wipes, alcohol-based handrub, and a control involving no intervention. All interventions were evaluated for mean reduction in colony-forming units (CFUs) under 2 contamination protocols: "whole hand" and "palmar surface." Results were analyzed according to a Bayesian approach, by using hierarchical models adjusted for multiple observations.

RESULTS

Under the whole-hand protocol, the greatest adjusted mean reductions were achieved by warm water with plain soap (2.14 log(10) CFU/mL [95% credible interval (CrI), 1.74-2.54 log(10) CFU/mL]), cold water with plain soap (1.88 log(10) CFU/mL [95% CrI, 1.48-2.28 log(10) CFU/mL), and warm water with antibacterial soap (1.51 log(10) CFU/mL [95% CrI, 1.12-1.91 log(10) CFU/mL]), followed by antiseptic hand wipes (0.57 log(10) CFU/mL [95% CrI, 0.17-0.96 log(10) CFU/mL]). Alcohol-based handrub (0.06 log(10) CFU/mL [95% CrI, -0.34 to 0.45 log(10) CFU/mL]) was equivalent to no intervention. Under the palmar surface protocol, warm water with plain soap, cold water with plain soap, and warm water with antibacterial soap again yielded the greatest mean reductions, followed by antiseptic hand wipes (26.6, 26.6, 26.6, and 21.9 CFUs per plate, respectively), when compared with alcohol-based handrub. Hypothenar (odds ratio, 10.98 [95% CrI, 1.96-37.65]) and thenar (odds ratio, 6.99 [95% CrI, 1.25-23.41]) surfaces were more likely than fingertips to remain heavily contaminated after handwashing.

CONCLUSIONS

Handwashing with soap and water showed the greatest efficacy in removing C. difficile and should be performed preferentially over the use of alcohol-based handrubs when contact with C. difficile is suspected or likely.

Quality and reporting of diagnostic accuracy studies in TB, HIV and malaria: evaluation using QUADAS and STARD standards

BACKGROUND

Poor methodological quality and reporting are known concerns with diagnostic accuracy studies. In 2003, the QUADAS tool and the STARD standards were published for evaluating the quality and improving the reporting of diagnostic studies, respectively. However, it is unclear whether these tools have been applied to diagnostic studies of infectious diseases. We performed a systematic review on the methodological and reporting quality of diagnostic studies in TB, malaria and HIV.

METHODS

We identified diagnostic accuracy studies of commercial tests for TB, malaria and HIV through a systematic search of the literature using PubMed and EMBASE (2004-2006). Original studies that reported sensitivity and specificity data were included. Two reviewers independently extracted data on study characteristics and diagnostic accuracy, and used QUADAS and STARD to evaluate the quality of methods and reporting, respectively.

FINDINGS

Ninety (38%) of 238 articles met inclusion criteria. All studies had design deficiencies. Study quality indicators that were met in less than 25% of the studies included adequate description of withdrawals (6%) and reference test execution (10%), absence of index test review bias (19%) and reference test review bias (24%), and report of uninterpretable results (22%). In terms of quality of reporting, 9 STARD indicators were reported in less than 25% of the studies: methods for calculation and estimates of reproducibility (0%), adverse effects of the diagnostic tests (1%), estimates of diagnostic accuracy between subgroups (10%), distribution of severity of disease/other diagnoses (11%), number of eligible patients who did not participate in the study (14%), blinding of the test readers (16%), and description of the team executing the test and management of indeterminate/outlier results (both 17%). The use of STARD was not explicitly mentioned in any study. Only 22% of 46 journals that published the studies included in this review required authors to use STARD.

CONCLUSION

Recently published diagnostic accuracy studies on commercial tests for TB, malaria and HIV have moderate to low quality and are poorly reported. The more frequent use of tools such as QUADAS and STARD may be necessary to improve the methodological and reporting quality of future diagnostic accuracy studies in infectious diseases.

Quantitative assessment of nuclear grooves in fine needle aspirates of the thyroid: a retrospective cytohistologic study of 94 cases

OBJECTIVE

To quantify the association between the percentage of nuclear grooves and papillary thyroid carcinoma (PTC) in fine needle aspirates (FNAs) of the thyroid.

STUDY DESIGN

All the thyroid FNA cases (n = 1,775) received at the McGill University Health Center Cytopathology Laboratory in 2003 and 2004 were retrieved. The 94 diagnostic FNAs with histologic followup were selected. The percentage of nuclear grooves was quantified manually by counting the number of grooves in 300 cells, at x400, in the areas where the nuclear grooves were most frequent. Using descriptive statistics and graphs, we evaluated the association between the percentage of nuclear grooving and 2 outcomes of surgical diagnosis.

RESULTS

The mean percentage of nuclear grooves was 23.7% in PTC vs. 9.44% in non-PTC cases. We identified the cut-off of 20% nuclear grooving as having the optimal positive predictive value of 80% for presence of PTC and negative predictive value of 77% for absence of PTC.

CONCLUSION

The presence of nuclear grooves in > or = 20% of cells, as counted in selective fields where grooves are the most frequent, is highly predictive of PTC.

Performance of purified antigens for serodiagnosis of pulmonary tuberculosis: a meta-analysis

Serological antibody detection tests for tuberculosis may offer the potential to improve diagnosis. Recent meta-analyses have shown that commercially available tests have variable accuracies and a limited clinical role. We reviewed the immunodiagnostic potential of antigens evaluated in research laboratories (in-house) for the serodiagnosis of pulmonary tuberculosis and conducted a meta-analysis to evaluate the performance of comparable antigens. Selection criteria included the participation of at least 25 pulmonary tuberculosis patients and the use of purified antigens. Studies evaluating 38 kDa, MPT51, malate synthase, culture filtrate protein 10, TbF6, antigen 85B, alpha-crystallin, 2,3-diacyltrehalose, 2,3,6-triacyltrehalose, 2,3,6,6'-tetraacyltrehalose 2'-sulfate, cord factor, and TbF6 plus DPEP (multiple antigen) were included in the meta-analysis. The results demonstrated that (i) in sputum smear-positive patients, sensitivities significantly >or=50% were provided for recombinant malate synthase (73%; 95% confidence interval [CI], 58 to 85) and TbF6 plus DPEP (75%; 95% CI, 50 to 91); (ii) protein antigens achieved high specificities; (iii) among the lipid antigens, cord factor had the best overall performance (sensitivity, 69% [95% CI, 28 to 94]; specificity, 91% [95% CI, 78 to 97]); (iv) compared with the sensitivities achieved with single antigens (median sensitivity, 53%; range, 2% to 100%), multiple antigens yielded higher sensitivities (median sensitivity, 76%; range, 16% to 96%); (v) in human immunodeficiency virus (HIV)-infected patients who are sputum smear positive, antibodies to several single and multiple antigens were detected; and (vi) data on seroreactivity to antigens in sputum smear-negative or pediatric patients were insufficient. Potential candidate antigens for an antibody detection test for pulmonary tuberculosis in HIV-infected and -uninfected patients have been identified, although no antigen achieves sufficient sensitivity to replace sputum smear microscopy. Combinations of select antigens provide higher sensitivities than single antigens. The use of a case-control design with healthy controls for the majority of studies was a limitation of the review. Efforts are needed to improve the methodological quality of tuberculosis diagnostic studies.

Efficient sampling approaches to address confounding in database studies

Administrative and other population-based databases are widely used in pharmacoepidemiology to study the unintended effects of medications. They allow investigators to study large case series, and they document prescription medication exposure without having to contact individuals or medical charts, or rely on human recall. However, such databases often lack information on potentially important confounding variables. This review describes some of the sampling approaches and accompanying data-analysis methods that can be used to assess, and deal efficiently with, such confounding.

Microvolt T-wave alternans as a predictor of mortality and severe arrhythmias in patients with left-ventricular dysfunction: a systematic review and meta-analysis

BACKGROUND

Studies have demonstrated that the use of implantable cardioverter defibrillators (ICDs) is effective for the primary prevention of arrhythmic events but due to imposing costs, there remains a need to identify which patients will derive the greatest benefit. Microvolt T-wave alternans (MTWA) has been proposed to assist in this stratification.

METHODS

We systematically searched the literature using MEDLINE, EMBASE, Current Contents, the Cochrane Library, INAHTA, and the Web of Science to identify all primary prevention randomized controlled trials and prospective cohort studies with at least 12 months of follow-up examining MTWA as a predictor of mortality and severe arrhythmic events in patients with severe left-ventricular dysfunction. The search was limited to full-text English publications between January 1990 and May 2007. The primary outcome was a composite of mortality and severe arrhythmias. Data were synthesized using Bayesian hierarchical models.

RESULTS

We identified no trials and 8 published cohort studies involving a total of 1,946 patients, including 332 positive, 656 negative, 84 indeterminate, and 874 non-negative (which includes both positive and indeterminate tests) MTWA test results. The risk of mortality or severe arrhythmic events was higher in patients with a positive MTWA compared to a negative test (RR = 2.7, 95% credible interval (CrI) = 1.4, 6.1). Similar results were obtained when comparing non-negative MTWA to a negative test.

CONCLUSION

A positive MTWA test predicts mortality or severe arrhythmic events in a population of individuals with severe left ventricular dysfunction. However, the wide credible interval suggests the clinical utility of this test remains incompletely defined, ranging from very modest to substantial. Additional high quality studies are required to better refine the role of MTWA in the decision making process for ICD implantation.

Identifying response shift statistically at the individual level

OBJECTIVE

The purpose of this study was to explore whether a longitudinal comparison between reported and predicted health could be used as a method of identifying subjects who potentially experienced response shift.

METHODS

A response-shift model was developed using data from a longitudinal study of stroke in which measures of stroke impact were made at study entry and at 1, 3, 6, and 12 months post stroke. Residuals from a random effects model were centered and used to create trajectories. This model was tested against a data set from a study in which the then-test had been administered. Twenty simulated data sets were also generated to examine how much of response shift could be attributed to random error.

RESULTS

Group-based trajectory analysis identified seven trajectory groups. The majority (67%) of the 387 persons showed no response shift over time, whereas 15% lowered and 13% raised their health over time, disproportionally to that predicted.

CONCLUSION

Results of the validation studies were supportive that this methodology identifies response shift, but further research is required to compare results with other methodologies and other predictive models.

Improving the estimation of tuberculosis infection prevalence using T-cell-based assay and mixture models

BACKGROUND

The prevalence of latent tuberculosis infection (LTBI) is traditionally estimated using the tuberculin skin test (TST). Highly specific blood-based interferon-gamma release assays (IGRAs) are now available and could enhance the estimation of LTBI prevalence in combination with model-based methods.

DESIGN

We compared conventional and model-based methods for estimating LTBI prevalence among 719 Indian health care workers who underwent both TST and QuantiFERON-TB Gold In-Tube (QFT-G). In addition to using standard cut-off points on TST and QFT-G, Bayesian mixture model analyses were performed with: 1) continuous TST data and 2) categorical data using both TST and QFT-G results in a latent class analysis (LCA), accounting for prior information on sensitivity and specificity.

RESULTS

Estimates of LTBI prevalence varied from 33.8% to 60.7%, depending on the method used. The mixture model based on TST alone estimated the prevalence at 36.5% (95%CI 28.5-47.0). When results from both tests were combined using LCA, the prevalence was 45.4% (95%CI 39.5-51.1). The LCA provided additional results on the sensitivity, specificity and predictive values of joint results.

CONCLUSION

The availability of novel, specific IGRAs and development of methods such as mixture analyses allow a more realistic and informative approach to prevalence estimation.

Validity of electron beam computed tomography for coronary artery disease: asystematic review and meta-analysis

BACKGROUND

Electron beam computed tomography (EBCT) is a method for measuring coronary calcification and has been promoted as a possible non-invasive screening/diagnostic tool for coronary artery disease (CAD). Our objective was to carry out a systematic review and meta-analysis of EBCT for the screening of asymptomatic patients and the diagnosis of symptomatic patients for CAD.

METHODS

Studies were identified from the PUBMED, MEDLINE, EMBASE, Current Contents, INAHTA and Cochrane Collaboration databases. We identified studies published in English evaluating EBCT using: (1) a prospective design among asymptomatic patients where CAD was measured in terms of clinical outcomes (e.g. myocardial infarction, death, revascularization); and (2)a cross-sectional design among symptomatic patients where CAD was measured by coronary angiography. We compared the risk of CAD in EBCT score categories defined as low (0-10), moderate (11-400) and high (>400). A hierarchical meta-analysis was used to pool risk ratios comparing categories across studies.

RESULTS

We identified 9 studies of asymptomatic patients and 10 studies of symptomatic patients. In both types of studies, we found variability in EBCT category distribution and risk of CAD within categories. For studies of asymptomatic patients we estimated the following risk ratios (95% credible intervals): moderate versus low 3.5 (2.4, 5.1) and high versus low 9.9 (5.3, 17.6). Similar results were obtained for studies of symptomatic patients. Ratios comparing the risk of no CAD among symptomatic patients were as follows: moderate versus low 0.5 (0.3, 0.8) and high versus low 0.12 (0.05, 0.2).

CONCLUSION

Increasing EBCT scores indicate higher risk for CAD in both asymptomatic and symptomatic patients. In general, asymptomatic patients with EBCT scores in the high category can perhaps be considered for preventive medical therapy and risk factor modification. Symptomatic patients with EBCT scores in the low category can perhaps, at least temporarily, avoid invasive coronary angiography. However, the non-uniform quality of studies and the lack of availability of individual-level data preclude the extension of our results to individual patients.

Sonographic features of breast carcinoma presenting as masses in BRCA gene mutation carriers

OBJECTIVE

The purpose of this study was to review the sonographic features of breast cancer gene BRCA1- and BRCA2-associated breast carcinomas in comparison with "sporadic" breast carcinomas and benign breast masses.

METHODS

Sonograms of 233 breast masses, including 33 BRCA-associated malignant masses (BRCA1, 15; BRCA2, 18), 148 sporadic malignant masses, and 52 benign masses, were reviewed by consensus by 2 radiologists according to American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) terminology.

RESULTS

Most of the sporadic and BRCA1-and BRCA2-associated cancers displayed an irregular shape (91.2%, 93.3%, and 83.3%, respectively). BRCA1-associated cancers showed microlobulated margins in 53.3% versus 33.8% (sporadic) and 33.3% (BRCA2). A parallel orientation was most frequently encountered in BRCA1-associated lesions (46.7%) versus sporadic (33.8%) and BRCA2 (33.3%), whereas posterior acoustic shadowing was least frequently seen in BRCA1-associated lesions (13.3%) versus BRCA2 (16.7%) and sporadic (31.1%). Most (73.3%) of the BRCA1-associated lesions were classified as BI-RADS category 4, whereas most of the sporadic and BRCA2-associated lesions were classified as BI-RADS category 5 (66.2% and 72.2%).

CONCLUSIONS

Sonographic features of BRCA-associated and sporadic breast carcinomas do not differ substantially. BRCA1-associated breast carcinomas trend toward less malignant sonographic characteristics, but strict application of the BI-RADS categorizations demands that they be classified as category 4 or 5.

Testing for HER2-positive breast cancer: a systematic review and cost-effectiveness analysis

BACKGROUND

Testing to determine HER2 status has come into focus since the approval of trastuzumab (Herceptin) for the treatment of HER2-positive breast cancer. We compared the cost-effectiveness of various strategies used to test HER2 status, an important first step toward evaluating the overall cost-effectiveness of trastuzumab therapy.

METHODS

We performed a systematic review of studies that evaluated concordance between immunohistochemistry and fluorescence in situ hybridization testing to determine HER2 status. We performed a meta-analysis to estimate the distribution of immunohistochemistry scores in each category (0, 1+, 2+, 3+) and the probability of receiving a positive result of fluorescence in situ hybridization (which we assumed to be the "gold-standard" test) for each category. We calculated the accuracy and incremental cost per accurate diagnosis for each testing strategy compared with the base strategy (immunohistochemistry testing, followed by confirmation of 2+ scores by fluorescence in situ hybridization).

RESULTS

The median percentage of patients in each category of immunohistochemistry score was: 0, 36.1%; 1+, 35.5%; 2+, 12.0%; and 3+, 16.2%. The median percentage of results of fluorescence in situ hybridization that were positive in each immunohistochemistry category was: 0, 1.6%; 1+, 4.9%; 2+, 29.8%; and 3+, 92.4%. The base strategy was expected to correctly determine the HER2 status of 96% of patients with breast cancer. Confirmation of the HER2 status by fluorescence in situ hybridization in cases that received a score of 3+ reduced the percentage of false-positive results to 0% and increased the percentage of accurately determined HER2 results to 97.6%. Compared with the base strategy, this strategy was associated with a median incremental cost-effectiveness ratio of $6175 per case of accurately determined HER2 status. The strategy of performing fluorescence in situ hybridization testing in all cases of breast cancer was associated with a median incremental cost-effectiveness ratio of $8401 per case of accurately determined HER2 status.

INTERPRETATION

The strategy with the lowest cost-effectiveness ratio involved screening all newly diagnosed cases of breast cancer with immunohistochemistry and confirming scores of 2+ or 3+ with fluorescence in situ hybridization testing.

The cost-effectiveness of drug-eluting stents: a systematic review

BACKGROUND

Drug-eluting stents have been seen as an attractive alternative to bare-metal stents for percutaneous coronary interventions (PCIs) because of the decreased need for revascularization. However, comparative clinical trials have shown no difference in patient outcomes, and drug-eluting stents are considerably more expensive than their bare-metal counterparts. We conducted a systematic review of all published comparative cost-effectiveness analyses to identify the factors contributing to the heterogeneity of their conclusions.

METHODS

We retrieved all articles published between Jan. 1, 2000, and July 31, 2006, in which the cost-effectiveness, from a third-party payer perspective, of drug-eluting stents was compared with that of bare-metal stents for PCI in unrestricted patient populations. Electronic databases, Web sites from health technology assessment groups and references of identified articles were searched. Our outcome variable was whether the study's conclusions favoured widespread use of drug-eluting stents, as assessed by 4 independent reviewers. Study characteristics such as quality, funding source, country and year of publication were extracted. Two-by-2 tables and Fisher's exact test were used to study the association between covariates and the outcome variable. A classification and regression tree (CART) model was used for multivariate analysis.

RESULTS

We identified 19 cost-effectiveness analyses. Ten were in favour of widespread use of drug-eluting stents, and 9 favoured more restrained use. Only 1 of 9 high-quality studies supported widespread use, as compared with 9 of 10 lower quality studies (p < 0.001). All of the 7 sponsored studies argued in favour of widespread use, as compared with 3 of the 12 studies without sponsorship (p = 0.003). Studies from the United States were more likely than those from other countries to endorse unlimited use (p = 0.032). A CART model with 2 covariates--study quality and sponsorship--provided the best fit (error rate 10.5%).

INTERPRETATION

Conclusions drawn by cost-effectiveness analyses of drug-eluting stents for PCI are associated with the study's quality, funding source and country of origin. Vigilance regarding these study characteristics is required when interpreting findings from cost-effectiveness analyses.

The role of gowns in preventing nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA): gown use in MRSA control

During a 2-year period, a standard isolation protocol for control of methicillin-resistant Staphylococcus aureus was compared with a similar protocol in which gowns were not used but the availability of alcohol-based hand disinfectant was increased. Intervention wards had 0.10 fewer new MRSA transmissions per ward per month, compared with control wards (P was not significant).

Systematic detection and multidisciplinary care of depression in older medical inpatients: a randomized trial

BACKGROUND

Major depression is a frequent and serious disorder in older medical inpatients. Because the condition goes undetected and untreated in most of these patients, we conducted a randomized clinical trial to evaluate the effectiveness of a strategy of systematic detection and multidisciplinary treatment of depression in this population.

METHODS

Consecutive patients aged 65 years or more admitted to general medical services in a primary care hospital between October 1999 and November 2002 were screened for depression with the Diagnostic Interview Schedule (DIS) within 48 hours after admission. Patients found to have major depression were randomly allocated to receive the intervention or usual care. The intervention involved consultation and treatment by a psychiatrist and follow-up by a research nurse and the patient's family physician. Research assistants, blind to group allocation, collected data from the patients at enrollment and at 3 and 6 months later using the Hamilton Depression Rating Scale (HAMD), the Medical Outcomes 36-item Short Form (SF-36), the DIS, the Mini-Mental State Examination (MMSE), the Older Americans Resources and Services (OARS) questionnaire to assess basic and instrumental activities of daily living (OARS-ADL and OARS-IADL) and the Rating Scale for Side Effects. Data on the severity of illness, length of hospital stay, health services and medication use, mortality and process of care were also collected. The primary outcome measures were the HAMD and SF-36.

RESULTS

Of 1500 eligible patients who were screened, 157 were found to have major depression and consented to participate (78 in the intervention group and 79 in the usual care group). At randomization, there were no clinically or statistically significant differences between the 2 groups. Sixty-four patients completed follow-up to 6 months, 57 withdrew, and 36 died. At 6 months, there were no clinically or statistically significant differences the 2 groups in HAMD or SF-36 scores or any of the secondary outcome measures.

INTERPRETATION

We were unable to demonstrate that systematic detection and multidisciplinary care of depression was more beneficial than usual care for elderly medical inpatients.