Evaluating the Safety of an Educational Deprescribing Intervention: Lessons from the Optimize Trial

BACKGROUND

Patients, family members, and clinicians express concerns about potential adverse drug withdrawal events (ADWEs) following medication discontinuation or fears of upsetting a stable medical equilibrium as key barriers to deprescribing. Currently, there are limited methods to pragmatically assess the safety of deprescribing and ascertain ADWEs. We report the methods and results of safety monitoring for the OPTIMIZE trial of deprescribing education for patients, family members, and clinicians.

METHODS

This was a pragmatic cluster randomized trial with multivariable Poisson regression comparing outcome rates between study arms. We conducted clinical record review and adjudication of sampled records to assess potential causal relationships between medication discontinuation and outcomes. This study included adults aged 65+ with dementia or mild cognitive impairment, one or more additional chronic conditions, and prescribed 5+ chronic medications. The intervention included an educational brochure on deprescribing that was mailed to patients prior to primary care visits, a clinician notification about individual brochure mailings, and an educational tip sheets was provided monthly to primary care clinicians. The outcomes of the safety monitoring were rates of hospitalizations and mortality during the 4 months following brochure mailings and results of record review and adjudication. The adjudication process was conducted throughout the trial and included classifications: likely, possibly, and unlikely.

RESULTS

There was a total of 3012 (1433 intervention and 1579 control) participants. There were 420 total hospitalizations involving 269 (18.8%) people in the intervention versus 517 total hospitalizations involving 317 (20.1%) people in the control groups. Adjusted risk ratios comparing intervention to control groups were 0.92 [95% confidence interval (CI) 0.72, 1.16] for hospitalization and 1.19 (95% CI 0.67, 2.11) for mortality. Both groups had zero deaths "likely" attributed to a medication change prior to the event. A total of 3 out of 30 (10%) intervention group hospitalizations and 7 out of 35 (20%) control group hospitalizations were considered "likely" due to a medication change.

CONCLUSIONS

Population-based deprescribing education is safe in the older adult population with cognitive impairment in our study. Pragmatic methods for safety monitoring are needed to further inform deprescribing interventions.

TRIAL REGISTRATION

NCT03984396. Registered on 13 June 2019.

Association Between Diabetes Severity and Risks of COVID-19 Infection and Outcomes

BACKGROUND

Little is known about whether diabetes increases the risk of COVID-19 infection and whether measures of diabetes severity are related to COVID-19 outcomes.

OBJECTIVE

Investigate diabetes severity measures as potential risk factors for COVID-19 infection and COVID-19 outcomes.

DESIGN, PARTICIPANTS, MEASURES

In integrated healthcare systems in Colorado, Oregon, and Washington, we identified a cohort of adults on February 29, 2020 (n = 1,086,918) and conducted follow-up through February 28, 2021. Electronic health data and death certificates were used to identify markers of diabetes severity, covariates, and outcomes. Outcomes were COVID-19 infection (positive nucleic acid antigen test, COVID-19 hospitalization, or COVID-19 death) and severe COVID-19 (invasive mechanical ventilation or COVID-19 death). Individuals with diabetes (n = 142,340) and categories of diabetes severity measures were compared with a referent group with no diabetes (n = 944,578), adjusting for demographic variables, neighborhood deprivation index, body mass index, and comorbidities.

RESULTS

Of 30,935 patients with COVID-19 infection, 996 met the criteria for severe COVID-19. Type 1 (odds ratio [OR] 1.41, 95% CI 1.27-1.57) and type 2 diabetes (OR 1.27, 95% CI 1.23-1.31) were associated with increased risk of COVID-19 infection. Insulin treatment was associated with greater COVID-19 infection risk (OR 1.43, 95% CI 1.34-1.52) than treatment with non-insulin drugs (OR 1.26, 95% 1.20-1.33) or no treatment (OR 1.24; 1.18-1.29). The relationship between glycemic control and COVID-19 infection risk was dose-dependent: from an OR of 1.21 (95% CI 1.15-1.26) for hemoglobin A1c (HbA1c) < 7% to an OR of 1.62 (95% CI 1.51-1.75) for HbA1c ≥ 9%. Risk factors for severe COVID-19 were type 1 diabetes (OR 2.87; 95% CI 1.99-4.15), type 2 diabetes (OR 1.80; 95% CI 1.55-2.09), insulin treatment (OR 2.65; 95% CI 2.13-3.28), and HbA1c ≥ 9% (OR 2.61; 95% CI 1.94-3.52).

CONCLUSIONS

Diabetes and greater diabetes severity were associated with increased risks of COVID-19 infection and worse COVID-19 outcomes.

Systematic surveillance of patient-reported symptoms of viral respiratory tract infectious Syndromes in diverse populations

BACKGROUND

Patient reported outcome measures (PROM) can improve patient care and be crucial for symptom tracking especially during disease outbreaks. FLU-PRO Plus is a validated PROM used to track viral respiratory symptoms. Our study aimed to evaluate the feasibility of using FLU-PRO© Plus, to track symptoms across three healthcare systems.

METHODS

The prospective, longitudinal study recruited adults between February-May 2021 from HealthPartners Institute (HP), Kaiser Permanente Georgia (KPGA), and Kaiser Permanente Mid-Atlantic States (KPMAS). Adult members were eligible if they had a positive lab or diagnosis for either COVID-19 or influenza-like illness (ILI) or exhibited 2 + viral respiratory symptoms. Descriptive statistics were calculated to describe the patient characteristics for participants that were eligible for FLU-PRO Plus, successfully contacted, attempted to log in to the FLU-PRO Plus website, and participants who completed FLU-PRO Plus Day 1. Bivariable and multivariable logistic regression using PROC GLIMMIXX investigated the patient characteristics associated with (1) successful contact and (2) FLU-PRO Plus Day 1 completion.

RESULTS

We identified a total of 15,650 eligible participants during the enrollment period: 9,582 from HP, 1,740 from KPGA, and 4,328 from KPMAS. Among the total of 409 eligible adults who attempted to participate in FLU-PRO Plus, 317 completed FLU-PRO Plus Day 1. Among the 317 individuals that completed FLU-PRO Plus Day 1, 205 (67.5%) were diagnosed with COVID-19; 112 adults diagnosed with COVID-19 completed FLU-PRO Plus Day 14. Among adults successfully contacted, adults aged 35-64 (OR = 1.40, 95% CI 1.05, 1.87), females (OR = 1.77, 95% CI 1.38, 2.27), and adults diagnosed with COVID-19 (OR = 1.66, 95% CI 1.27, 2.17) had higher odds of completing FLU-PRO Plus Day 1; Asian adults (OR = 0.38, 95% CI 0.19, 0.76) and Black and African American adults (OR = 0.33, 95% CI 0.19, 0.76) had lower odds compared to White adults.

CONCLUSION

Our study reports on the feasibility of patients across three integrated healthcare systems utilizing FLU-PRO Plus to monitor their respiratory symptoms. Patient reported outcome measures (PROM) can improve patient care, quality of life, and reduce the strain of limited resources on healthcare systems. Future FLU-PRO Plus studies should develop an implementation strategy to fully integrate FLU-PRO Plus within clinical care and patient management.

Variation in Colorectal Cancer Stage and Mortality across Large Community-Based Populations: PORTAL Colorectal Cancer Cohort

INTRODUCTION

Colorectal cancer (CRC) incidence and mortality can be reduced by effective screening and/or treatment. However, the influence of health care systems on disparities among insured patients is largely unexplored.

METHODS

To evaluate insured patients with CRC diagnosed between 2010 and 2014 across 6 diverse US health care systems in the Patient-Centered Outcomes Research Institute (PCORI) Patient Outcomes Research To Advance Learning (PORTAL) CRC cohort, we contrasted CRC stage; CRC mortality; all-cause mortality; and influences of demographics, stage, comorbidities, and treatment between health systems.

RESULTS

Among 16,211 patients with CRC, there were significant differences between health care systems in CRC stage at diagnosis, CRC-specific mortality, and all-cause mortality. The unadjusted risk of CRC mortality varied from 27% lower to 21% higher than the reference system (hazard ratio [HR] = 0.73, 95% confidence interval = 0.66-0.80 to HR = 1.21, 95% confidence interval = 1.05-1.40; p < 0.01 across systems). Significant differences persisted after adjustment for demographics and comorbidities (p < 0.01); however, adjustment for stage eliminated significant differences (p = 0.24). All-cause mortality among patients with CRC differed approximately 30% between health care systems (HR = 0.89-1.17; p < 0.01). Adjustment for age eliminated significant differences (p = 0.48).

DISCUSSION

Differences in CRC survival between health care systems were largely explained by stage at diagnosis, not demographics, comorbidity, or treatment. Given that stage is strongly related to early detection, these results suggest that variation in CRC screening systems represents a modifiable systems-level factor for reducing disparities in CRC survival.

Melanoma incidence, recurrence, and mortality in an integrated healthcare system: A retrospective cohort study

Background

Numerous studies have examined melanoma incidence and survival, but studies on melanoma recurrence are limited. We examined melanoma incidence, recurrence, and mortality among members of Kaiser Permanente Colorado (KPCO) between January 1, 2000 and December 31, 2015.

Methods

Age‐adjusted incidence rates were computed to examine trends among KPCO members aged 21 years and older. Cox proportional hazards models were used to examine factors associated with recurrence and mortality.

Results

Our cohort included 1931 cases of invasive melanoma. Incidence rates increased over time and were higher than SEER rates; however, the increase was limited to early stage disease. In multivariable models, stage at initial diagnosis, gender, and age were associated with melanoma recurrence. Men were more likely to have a recurrence than women (adjusted hazard ratio [HR]: 1.70, 95% confidence interval [CI]: 1.19‐2.43), and for each decade of increasing age, the adjusted HR = 1.20 (95% CI: 1.06‐1.37). Factors associated with all‐cause mortality included stage (HR = 12.87, 95% CI: 6.63‐24.99, for stage IV vs stage I), male gender (HR = 1.42, 95% CI: 1.12‐1.79), older age at diagnosis, lower socioeconomic status, and comorbidity index. For melanoma‐specific mortality, results were similar, with one exception: age was not associated with melanoma‐specific death (HR = 1.09, 95% CI: 0.94‐1.25, P = 0.253).

Conclusions

Data derived from an insured patient population, such as KPCO, have the potential to enhance our understanding of emerging trends in melanoma. This is the first population‐based study in the United States to examine patient characteristics associated with risk of recurrence. Men have an increased risk of both recurrence and death, and thus may benefit from more intensive follow‐up than women.

Tumor characteristics and treatment in early-onset colorectal cancer

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Background: While overall incidence and mortality of colorectal cancer (CRC) has declined, incidence and mortality are increasing in those < 50 years old (early-onset CRC). Our objective was to better understand early-onset CRC by comparing tumor characteristics and initial treatment type between early-onset and normal/late-onset CRC. Methods: We used health system and national tumor registries to identify patients diagnosed with adenocarcinoma of the colon or rectum from 2010-2014 at 6 US integrated health systems in the Patient Outcomes To Advance Learning (PORTAL) network. Tumor registry data included: age at diagnosis, stage, grade, anatomic site, histology, number of lymph nodes examined, and receipt of initial systemic therapy (chemotherapy or immunotherapy). Demographics and other patient characteristics were obtained from the EHR. We used logistic regression to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) comparing the distribution of tumor characteristics and treatment patterns in early-onset ( < 50 years old) vs. normal/late-onset CRC. Results: There were 1,424 early-onset and 10,810 normal/late onset CRC cases in our analyses. Compared to normal/late onset cases, patients with early-onset CRC were more likely to be Hispanic, obese, never smokers, and to have Charlson comorbidity scores < 3. After adjustment for patient characteristics, compared to normal/late onset CRC, early-onset CRC was associated with more advanced stage disease (OR for stage 4 vs. stage 1 = 2.8, CI: 2.4-3.4), high grade histology (OR for poorly differentiated/undifferentiated vs. well/moderately differentiated = 1.2, CI: 1.1-1.5), signet ring histology (OR for signet ring vs. non-mucinous adenocarcinoma = 1.7, CI: 1.1, 2.6), and rectal (OR for rectum vs. cecum = 2.4, CI: 1.9-2.9) or left colon location (OR for left colon vs. cecum = 2.2, CI: 1.8-2.8). After adjustment for patient and tumor characteristics, early-onset patients were more likely than normal/late onset patients to have > 12 lymph nodes examined (OR = 1.6, CI: 1.4-1.8) and to receive systemic therapy (OR = 2.8, CI: 2.4, 3.4). Conclusions: Early-onset CRC is associated with aggressive tumor characteristics, distal location, and systemic therapy use.

The predicted role of steric specificity in crowding-mediated effects on reversible biomolecular association

A fundamental question in biology is whether the presence of non-reacting macromolecules in the cytoplasm affects the rates and extents of reversible association reactions, a phenomenon often referred to as 'macromolecular crowding.' Under certain conditions, crowding has been proposed to dramatically alter the kinetics and thermodynamics of chemical reactions, making it difficult to quantitatively relate rates and extents of reactions measured in vitro to those occurring in vivo. In this work, we use Brownian dynamics simulation and Monte Carlo methods to (1) quantify the overall thermodynamic and kinetic effects of crowding by independently investigating each step of reversible bimolecular association (i.e. translational diffusion, steric specific binding, and dissociation), and (2) provide an explicit, quantitative investigation of how the degree of steric specificity of protein dimerization influences crowding-mediated effects on association and dissociation. We find that k on decreases by ∼2-fold for non-steric specific reactions, and increases by ∼3-fold for highly steric specific reactions. In addition, k off decreases by only ∼30%-60% in the presence of crowders, depending on the strength of the bond between the reactant pair, so that the equilibrium constant is increased by ∼4-fold, at most. These results suggest that crowding-mediated effects on globular protein dimerization reactions in the cytoplasm are modulated by the steric specificity of the reactants, and that reversible protein-protein association is relatively insensitive to the physical presence of crowders (i.e. steric repulsion effects in the cytoplasm) for crowders of similar size and shape to reactants over a range of volume fractions (0-0.3).

Predictors of a child's ability to use a visual analogue scale

BACKGROUND

Visual analogue scales (VAS) are used to assess the strength of perceptions of both children and adults in many clinical and research settings. Although the VAS has been shown by some authors to be reliable for use by children aged 5 years and older, others have proposed that young children, generally < or =7 years of age, may not have the conceptual ability to use a VAS.

OBJECTIVE

To identify demographic and cognitive variables that would maximize the accuracy of predicting children's abilities to use a VAS.

METHODS

Forty kindergarten children performed a seriation task, used a VAS to perform a calibration task and completed the Block Design and Vocabulary subtests of the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R). An estimated IQ was calculated from the WPPSI-R subtest scores. Socioeconomic status was assessed using the Hollingshead Four Factor Index of Social Status. Logistic regression was used to determine the best predictive models. Sensitivity, specificity, negative predictive value, positive predictive value and accuracy were calculated for statistically significant predictive models.

MAIN OUTCOME MEASURE

Successful completion of the calibration study by the child.

RESULTS

Only 42% of the subjects could use a VAS. The subject's age (> or =5.6 years), combined with estimated IQ (> or =100), was the best predictor of a child's ability to use a VAS (88% accuracy).

CONCLUSION

The majority of kindergarten children in our study could not complete a VAS accurately. Cognitive ability, combined with chronological age, was the best predictor of a child's accurate use of a VAS, as determined by logistic regression. Paediatric researchers may need to consider alternative rating scales to measure perceptions in children under 7 years of age.

Statistical comparison of dissolution curves

The purpose of this investigation was to develop statistical procedures to determine if two sets of dissolution curves could have come from the same population of curves. The f(2)statistic developed by the Food and Drug Administration, FDA, has been shown to have many limitations and is too liberal in concluding similarity between dissolution profiles. The procedure currently used by the FDA involves computing the mean amount dissolved at each time and then comparing the two mean curves. This approach ignores all of the variability within sets of profiles, which, from a statistical viewpoint, is a serious limitation. This investigation presents three different statistics for comparison of dissolution curves with associated decision rules and power functions. These three statistics are extensions of existing procedures: (1) an extension of the Mann--Whitney test which compares the variability within each set of profiles and between the two sets; (2) an extension of the Kolmogorov--Smirnov D statistic which compares three empirical cumulative distribution functions; and (3) an adaptation of the well known chi-squared test. A computer program, which includes the algorithm for each of the three statistics and varying sample sizes, is also available.

On the determination of bioequivalence

The characteristics and advantages of a new method for the determination of bioequivalence are described. This method does not employ AUC or Cmax, therefore it does not depend on a number of assumptions usually needed for the validity of the traditional method.

Prilocaine-phenylephrine topical anesthesia for repair of mucous membrane lacerations

OBJECTIVE

To compare the effectiveness of prilocaine-phenylephrine (Prilophen), a new topical anesthetic that does not contain cocaine, to that of lidocaine infiltration during repair of lacerations on or near mucous membranes in children.

DESIGN

A prospective, randomized, blinded trial.

SETTING

The emergency department of a large academic children's hospital.

PATIENTS

Children one year of age or older with a laceration 5 cm or less in length on or near a mucous membrane.

INTERVENTIONS

Forty patients were randomly assigned one of the two local anesthetics, with 20 patients in each treatment group.

OUTCOME MEASURES

Pain felt during suturing was scored by suture technicians, research assistants, a videotape reviewer, parents, and patients five years of age and older using a visual analog scale (VAS).

RESULTS

There was no statistically significant difference in performance between topical Prilophen and lidocaine infiltration when VAS pain scores of research assistants, parents, and patients were compared. However, lidocaine infiltration performed significantly better than topical Prilophen when comparing VAS scores of suture technicians (P = 0.003) and the videotape reviewer (P = 0.02). When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 2 units for VAS scores of suture technicians, 2 VAS units for research assistants, 3 VAS units for the videotape reviewer and parents, and 7 VAS units for patients. There were no wound healing or other complications.

CONCLUSIONS

Prilophen is a new topical anesthetic alternative to lidocaine infiltration for closure of lacerations on or near mucous membranes, where use of tetracaine-adrenaline-cocaine is contraindicated. The performance of Prilophen was rated by two of the observer groups as statistically inferior to that of lidocaine infiltration; however, the differences in pain scores were small and may not be clinically significant. Further investigation of this new topical anesthetic is warranted.

Tetracaine-lidocaine-phenylephrine topical anesthesia compared with lidocaine infiltration during repair of mucous membrane lacerations in children

This study compared the effectiveness of a new topical anesthetic, tetracaine-lidocaine-phenylephrine (TetraLidoPhen), with that of lidocaine infiltration during repair of mucous membrane lacerations in children. It was conducted in the emergency department of an urban children's hospital with use of a prospective, randomized, blinded study design. Participants were 90 children 1 year of age or older with a laceration 5 cm or less in length on or near a mucous membrane that required suturing. They were randomly assigned to one of two treatment groups, with 45 patients in each group. Pain felt during suturing was scored by suture technicians, research assistants, a videotape reviewer, parents, and patients 5 years of age and older using a Visual Analogue Scale (VAS). Suture technicians, research assistants, a videotape reviewer, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an Anesthesia Effectiveness scale and a Wound Blanching scale. The laceration was located near the eyes in 71 patients (79%), and on or near the lips in 19 (21%). Lidocaine infiltration performed significantly better than topical TetraLidoPhen in comparisons of Likert scores of suture technicians (P = 0.007), research assistants (P = 0.005), the videotape reviewer (P = 0.003), and parents (P = 0.03); Anesthetic Effectiveness scale scores of suture technicians (P = 0.00002; relative risk (RR) = 1.83, 95% confidence interval 1.36 < RR < 2.46); and VAS scores of suture technicians (P = 0.002), research assistants (P = 0.001), and the videotape reviewer (P = 0.005). No significant difference in performance was detected between lidocaine and TetraLidoPhen in comparing VAS scores of parents and patients. There was a 4.4% wound complication rate, including two (2.2%) wound infections. The authors conclude that TetraLidoPhen is a new topical anesthetic that appears to be safe when applied on or near mucous membranes. Its performance among study participants was statistically inferior to that of lidocaine infiltration; however, the differences in pain scores were small and may not be clinically significant. Also, comparisons of pain scores in this study did not take into account the pain associated with the initial injection of lidocaine. Therefore, study findings may underestimate the comparative performance of TetraLidoPhen. Further investigation of this new topical anesthetic is warranted.

Prilocaine-phenylephrine and bupivacaine-phenylephrine topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

The effectiveness of two new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine and bupivacaine-phenylephrine) was compared with that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. This study was a prospective, randomized, double-blind trial conducted in the emergency department of a large children's hospital. Participants were 180 children 1 year of age or older with a laceration 5 cm or less in length that required suturing. Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients 5 years of age and older using a visual analogue scale (VAS). There was no statistical difference demonstrated between the effectiveness of prilocaine-phenylephrine and that of TAC for any of the observer groups. A statistically significant difference was seen among anesthetics when comparing VAS scores of research assistants (P = .002), suture technicians (P = .006), and parents (P = .03), but not when comparing VAS ratings of patients (P = .07). Based on Tukey's post hoc test, these statistically significant differences were between TAC and bupivacaine-phenylephrine. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.3 VAS units for each rater group. In conclusion, this study demonstrated the effectiveness and safety of prilocaine-phenylephrine and bupivacaine-phenylephrine. Prilocaine-phenylephrine statistically outperformed bupivacaine-phenylephrine and offers an effective alternative to TAC during laceration repair in children.

New non-cocaine-containing topical anesthetics compared with tetracaine-adrenaline-cocaine during repair of lacerations

OBJECTIVE

To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children.

DESIGN

Prospective, randomized, double-blind clinical trial.

SETTING

The emergency department of an urban children's hospital.

PARTICIPANTS

Children 1 year of age or older with a laceration </= 5 cm in length that required suturing. Intervention. A total of 240 children were randomly assigned to one of four treatment groups.

OUTCOME MEASURES

Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients >/= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale.

RESULTS

There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79).

CONCLUSION

This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children.

Comparison of topical anesthetics with lidocaine infiltration during laceration repair in children

This study is a randomized, blinded trial that compares the effectiveness of a new topical anesthetic preparation of 2% mepivacaine and 1:100,000 norepinephrine (Mepivanor); a topical solution of 1% tetracaine, 1:4,000 adrenaline, and 4% cocaine (TAC); and 1% lidocaine infiltration during laceration repair in children. The study was conducted in the emergency department of a large academic children's hospital. Study participants were children 2 years of age or older with a laceration on the face or scalp, 5 cm or less in length, that required suturing. Patients were randomly assigned to receive Mepivanor topical solution, TAC topical solution, or lidocaine infiltration anesthesia prior to laceration repair. Seventy-one patients were enrolled in the study during a 2-month period. Outcome measures assessed pain perceptions using a Visual Analogue Scale (VAS) and a seven-point Likert scale. There was statistical power to detect differences of 1.2 to 1.7 units for the VAS outcome measures using alpha = 0.05 and beta = 0.20. There were no statistically significant (P > 0.05) differences between TAC and 1% lidocaine infiltration in providing effective anesthesia. Mepivanor was generally less effective in providing adequate anesthesia during laceration repair than TAC and lidocaine infiltration, with Tukey's post hoc test for ANOVA demonstrating statistically significant (P < 0.05) differences between Mepivanor and these agents for research assistant and suture technician VAS scores. Wound blanching was judged to be less with Mepivanor than with TAC, although this difference was not statistically significant. There were no adverse reactions, wound infections, or healing difficulties for any of the patients who received TAC or Mepivanor. It was concluded that non-cocaine-containing Mepivanor was generally less effective than TAC and lidocaine infiltration in providing adequate local anesthesia during laceration repair. TAC containing only 120 mg of cocaine (3 mL of 4% cocaine) was as effective as 1% lidocaine infiltration in providing local anesthesia during laceration repair. This will allow the amount of cocaine in TAC to be reduced, thereby decreasing costs and the likelihood of adverse reactions.

Comparison of topical anesthetics without cocaine to tetracaine-adrenaline-cocaine and lidocaine infiltration during repair of lacerations: bupivacaine-norepinephrine is an effective new topical anesthetic agent

OBJECTIVE

To compare the effectiveness of four topical anesthetics that do not contain cocaine with that of topical tetracaine-addrenaline-cocaine (TAC) and lidocaine infiltration during laceration repair in children.

DESIGN

This was a randomized, blinded trial.

SETTING

The study was conducted in the emergency department of a large children's hospital.

PARTICIPANTS

Subjects were children 2 years of age or older with a laceration 5 cm or less in length that required sururing.

INTERVENTIONS

Patients were randomly assigned to receive one of four noncocaine-containing topical anesthetics, topical TAC, or lidocaine infiltration anesthesia before laceration repair.

OUTCOME MEASURES

Outcome measures assessed pain perceptions using a Visual Analogue Scale, Likert scale, and Anethetic Effectiveness scale. Distress behaviors of patients were measured with the Restrained Infants and Children Distress Rating Scale.

RESULTS

Two hundred forty patients were enrolled in the study. Using alpha = 0.05 and beta = 0.2, there was statistical power to detect differences of 0.3 to 1.3 U for the outcome measures used. The bupivacaine-norepinephrine topical solution (Bupivanor) performed better than the other three new topical preparations. It provided effective wound anesthesia during lacertion repair, especially for lacerations of the face and scalp, where it was consistently rated as effective as TAC and 1% lidocaine infiltration by all observer groups for all outcome measures. There was a 4% overall wound complication, including one wound infection.

CONCLUSION

Bupivanor is an effective alternative to TAC and lidocaine infiltration for local anesthesia during laceration repair, expecially on the face and scalp. The effectiveness of Bupivanor on the face is important, because it is here where TAC is most likely inadvertently to come into contact with mucous membranes and result in systemic toxicity. Because pain and distress scores did not take into consideration the pain associated with the initial injection of lidocaine, the findings of this study conservatively estimate Bupivanor's effectiveness, compared with lidocaine infiltration.

Population requirements for capitation planning in pediatric cardiac surgery

OBJECTIVE

To determine the population number necessary to generate a sufficient volume of pediatric cardiac surgeries to allow accurate prediction of resource utilization.

DESIGN

All pediatric cardiac surgical patients receive care in our institution by means of only four clinical pathways that are based on acuity, not diagnosis or procedure. This allows accurate tracking of resource utilization. Based on available information, 750 consecutive surgically treated patients were retrospectively assigned to a pathway. They were subsequently subdivided into study groups of decreasing sizes from 150 to 35. Variability of pathway distribution from group to group was examined as a measure of the ability to predict resource utilization based on group size. Pediatric cardiac statistics from the state of Ohio were then used to extrapolate to the population base necessary to generate each group size.

SETTING

A regional pediatric cardiac referral center.

PATIENTS

All sequential patients who underwent pediatric cardiac surgery between July 1991 and January 1994.

RESULTS

Statewide statistics showed that a population base of 1 million people generates 100 pediatric cardiac operations. Groups of 100 patients or greater had minimal variation in pathway distribution from group to group, allowing accurate prediction of hospital charges. This was not true for groups of 50 patients or less.

CONCLUSIONS

Resource utilization for pediatric cardiac surgery can be accurately predicted in a capitated setting for populations of 1 million covered lives (100 procedures) or greater. For populations of 500 000 covered lives or less, variability of case mix is great enough to suggest the need for a more individualized payment mechanism.

Seizure classification in dogs from a nonreferral-based population

On initial evaluation for onset of seizure disorders at nonreferral veterinary practices, 50 previously healthy dogs were enrolled in a study to determine the probability of identifying a specific cause for the seizures. Treatment was not administered prior to entry of dogs in the study. On the basis of antemortem and postmortem test results, 22 dogs (44%) were classified as having primary epileptic seizures (PES; idiopathic or without identifiable cause), 23 (46%) had secondary epileptic seizures (SES; identifiable intracranial cause), and 5 (10%) had reactive epileptic seizures (RES; metabolic or transient noxious cause). Forty-one dogs (82%) had 2 or more seizures before evaluation, with 37 (90%) of these dogs classified as having epilepsy on the basis of an underlying chronic brain disorder. For these 41 dogs, 17 (41%) had PES, 20 (49%) had SES, and 4 (10%) had RES. Among the 9 dogs (18%) with nonrecurring seizures, 5 had PES, 3 had SES, and 1 had RES. Generalized seizures were the most common first-observed seizure type associated with all etiologic classifications in all dogs with recurring and nonrecurring seizures. Diagnosis of SES was statistically more probable when the dog was less than 1 or more than 7 years old at the first seizure, when the first seizure was a partial seizure, or when the first seizure occurred between midnight and 8 AM. A diagnosis of RES was statistically more probable only when the interval between the first and second seizure was brief (< or = 4 weeks).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical pathways can be based on acuity, not diagnosis

The standardization of medical practice is gaining acceptance as a technique for controlling length of stay and hospital charges, while maintaining quality. Most clinical pathways address specific diagnoses or procedures, but we have developed a new approach in which pathways for cardiac care are based on acuity. All congenital cardiac surgical care rendered at Columbus Children's Hospital now falls within one of four such clinical pathways. This simplified approach is easy to use and has been well accepted. Our experience in a group of 107 consecutive patients treated in this fashion is described. The results of variance analyses, along with length of stay and charge data, are presented to demonstrate the degree to which resource utilization can be standardized in this widely variable group of patients whose problems were made cohesive by classification according to acuity level. We conclude that the resultant standardization offers considerable advantages for the managed care environment.

Statistical considerations in pharmacokinetic study design

Pharmacokinetic studies may generally be categorised into 3 types: (a) population-based investigations, (b) individual-based compartmental, or (c) individual-based noncompartmental research projects. Each type of study has advantages and limitations. Population-based investigations pool drug concentrations across more than 1 individual subject. From these data, estimates of pharmacokinetic parameters are calculated. NONMEM is the only computer program available to evaluate this type of information. Recently a method has been proposed which derives individual estimates from the information available from NONMEM. By combining these 2 procedures it is possible for the clinician to review and adjust the dosage regimen if necessary. Population-based studies require fewer design criteria than other methods and are adaptable to the clinical setting, i.e. subjects can be patients currently being treated with the drug under consideration. One distinct advantage to this type of study is the flexibility of sampling times and the capability of the clinician to use information from the critically ill, the geriatric patient or the very young child. These subjects would not be available for the individual-based type of study because of the relatively large number of samples needed. Individual-based pharmacokinetic studies can be divided into 2 types with respect to their evaluation: (a) compartmental and (b) noncompartmental investigations. The latter type of study was originally thought to require fewer assumptions than the former but subsequently it has been shown that noncompartmental analyses are more restrictive and are basically compartmental in their approach. These studies estimate parameters which the compartmental investigation does not usually consider. These include area under the moment curve (AUMC) and mean residence time (MRT).(ABSTRACT TRUNCATED AT 250 WORDS)

Accuracy of references and quotations in veterinary journals

The accuracy of references and quotations used to substantiate statements of fact in articles published in 6 frequently cited veterinary journals was examined. Three hundred references were randomly selected, and the accuracy of each citation was examined. A subset of 100 references was examined for quotational accuracy; ie, the accuracy with which authors represented the work or assertions of the author being cited. Of the 300 references selected, 295 were located, and 125 major errors were found in 88 (29.8%) of them. Sixty-seven (53.6%) major errors were found involving authors, 12 (9.6%) involved the article title, 14 (11.2%) involved the book or journal title, and 32 (25.6%) involved the volume number, date, or page numbers. Sixty-eight minor errors were detected. The accuracy of 111 quotations from 95 citations in 65 articles was examined. Nine quotations were technical and not classified, 86 (84.3%) were classified as correct, 2 (1.9%) contained minor misquotations, and 14 (13.7%) contained major misquotations. We concluded that misquotations and errors in citations occur frequently in veterinary journals, but at a rate similar to that reported for other biomedical journals.

The lipid composition of milk from mice fed high or low fat diets

Total fatty acids and the proportions of methyl esters of individual fatty acids were measured in mouse milk. Pregnant mice were fed either a high fat (HF) diet or a low fat (LF) diet from 14 days of gestation. After parturition, each dam was milked once a day for a period of 18 days. The mean total fatty acid concentration over the entire study period was 110 mg/g of milk (approximately 11.7% fat as triglyceride) for both dietary treatment groups. During days 2 to 6 postpartum, the mean total fatty acid concentration for dams fed HF diet was lower than for the LF group. Although the concentration of total fatty acids of mouse milk was not affected by the level of dietary fat fed to the dam, several variations in the proportions of individual fatty acids were observed.

Body weights of C3H/HeN mice fed semipurified or commercial diets of different fat content

Oncology studies often require specially formulated diets to be fed to laboratory animals. To determine the effect of dietary fat on body weight, C3H/HeN mice were carefully assigned by weight into three groups. The first group was fed a high-fat semipurified diet (23% fat by weight) from 21 to 73 days of age then returned to a low-fat semipurified diet (5% fat by weight). A second group was fed the low-fat diet from 21 to 73 days of age, then the high-fat diet until 129 days of age, then returned to the low-fat diet. A final group was fed a 4.5% fat commercial diet for the entire 193-day study. The results showed that the mice fed the semipurified diets did not differ significantly from each other in weight over the course of the study but did differ significantly between 21 and 73 days of age, possibly from a taste preference for the high-fat diet. Mice fed the commercial diet always weighed significantly less. It was estimated that mice fed the commercial diet consumed more food and were less efficient in their food utilization. Mice should be carefully assigned, by weight, into experimental groups, and all groups, including untreated controls, should be fed the same type of diet.

Construction of best confidence intervals for half-lives

This paper presents a method of determining a confidence interval for the drug half-life based on statistical properties of the estimates of the disappearance rate constant of the drug. This interval is shown to be of minimum length which indicates it is a more precise estimate than others currently in use. A computer program to construct these intervals is available upon request.

Clinicopathologic findings in dogs with renal amyloidosis: 59 cases (1976-1986)

The medical records of 59 dogs with renal amyloidosis were reviewed. Most dogs with amyloidosis were greater than 6 years old, and females were affected more often than males. Beagles, Collies, and Walker Hounds were at increased risk, whereas German Shepherd Dogs and mixed-breed dogs were at decreased risk. Common historical findings were anorexia, polyuria, polydipsia, lethargy, vomiting, and weight loss. Common laboratory findings were leukocytosis, lymphopenia, nonregenerative anemia, hypercholesterolemia, azotemia, hyperphosphatemia, metabolic acidosis, isosthenuria, cylindruria, and proteinuria. Proteinuria was moderate to severe in most dogs, as assessed by qualitative determination of urine protein concentration, urine protein/urine creatinine ratio, and 24-hour urine protein excretion. Conservative medical management was of little value, and survival ranged from 3 to 20 months in 12 dogs for which this information was available. Moderate to severe diffuse global glomerular amyloidosis was detected in all dogs. Medullary amyloid deposition was multifocal and less severe, but was evident in most dogs. Secondary tubulointerstitial and glomerular lesions were mild or absent in most dogs. Thromboembolism was identified in approximately 14% of affected dogs, underlying inflammatory disease in 37%, and neoplasia in 20%. Laboratory indicators of renal function correlated poorly with histologic lesions, with the exception of glomerular amyloid deposition and "chronic renal disease" index with endogenous creatinine clearance.

Single- and repeat-dose pharmacokinetic studies of chloramphenicol in horses: values and limitations of pharmacokinetic studies in predicting dosage regimens

A single-dose pharmacokinetic study of chloramphenicol in propylene glycol was done in 6 horses after 22 mg/kg was administered IV. Serum drug concentrations obtained at various predetermined intervals were determined by an electroncapture gas-chromatographic technique. The time-concentration data were described by a 2-compartment open model, and various pharmacokinetic variables were estimated. The median elimination rate constant was estimated to be -0.0185 minute-1 (-0.0225 to -0.0148 minute-1), and the median half-life was 37.36 minutes (30.74 to 46.90 minutes). The median apparent volume of distribution and total body clearance were 1.46 L/kg (1.13 to 1.60 L/kg) and 25.56 ml/kg/min (23.66 to 32.21 ml/kg/min), respectively. On the basis of these data, single- and repeat-dose kinetic studies were done in another group of 6 animals. The drug was administered at a dosage of 22 mg/kg every 4 hours for 3 days. Blood samples were obtained for pharmacokinetic studies after the first and the last doses were given. The half-life, volume of distribution, and total body clearance did not change significantly (Wilcoxon signed rank test) after 3 days of therapy with chloramphenicol. The IV dose schedule for treating bacterial infections with organisms of different sensitivities has been determined from the estimates of the pharmacokinetic variables. The limitations of calculating the dose schedules for chloramphenicol on the basis of pharmacokinetic variables in horses are discussed.

Pharmacokinetics of florfenicol in veal calves

The pharmacokinetic disposition of florfenicol was described in veal calves after administration of a single 22-mg/kg dose intravenously, orally after a 12-h fast and orally 5 min post feeding. Both serum concentrations and urinary excretion were studied. After intravenous administration the median elimination half-life was 171.9 min while the half-life of the distribution phase was 5.9 min. The median body clearance (Cl) and apparent volume of distribution (Vz) were 2.85 ml/kg/min and 0.78 l/kg, respectively. Following oral administration the median bio-availability (f) was 0.88 for calves dosed after a 12-h fast and 0.65 for calves dosed 5 min post feeding. Calves given the oral doses had a complex absorption pattern with delayed absorption. Slightly more than 50% of the administered dose both orally and intravenously was recovered as unchanged florfenicol in the urine by 30 h.

Pedigree analysis of Abyssinian cats with familial amyloidosis

Pedigrees of 62 Abyssinian cats with familial amyloidosis were compared with those of 100 Abyssinian cats registered with the Cat Fanciers Association. The inbreeding coefficients of the 2 samples of cats were not significantly different. Analysis of the pedigrees with respect to specific ancestors, however, showed that certain cats were significantly more common in the pedigrees of affected cats than in those of cats in the randomly selected sample. These data support a genetic basis for this disease, but do not allow determination of the mode of inheritance.

A health index to evaluate clinically a beta-hemolytic streptococcal infectious disease model in the horse

Quantification of the clinical manifestations of a disease has been a serious problem particularly as related to clinical trials or drug efficacy studies. Historically, this quantification has been limited to categorizing each patient into one of three or four groups, e.g. worse, no improvement, improved. This problem becomes serious when an investigation utilizes an experimentally induced animal disease model. A health index, which quantifies the clinical state of horses which have an experimentally induced beta-hemolytic streptococcal infection, is described. Aspects of experimental design and statistical analysis are also discussed in relationship to the use of the index for drug efficacy studies.

Standardization of an experimental disease model of Streptococcus zooepidemicus in the equine

A reproducible experimental disease model in horses using Streptococcus zooepidemicus was developed. An intravenous challenge dose of 1 X 10(10) colony-forming units (CFU), followed 24 h later with another challenge of 1 X 10(8) CFU of Strep. zooepidemicus produced the desired disease model. The disease was characterized by depression, pyrexia, anorexia, abnormal lung sounds, inflammation of joints, moderate to severe lameness, gradual loss of condition and emaciation. The effects of the disease on hematology, serum chemical profile and different protein fractions were studied. The disease state had no effect on serum glucose, sodium, potassium, chloride, urea nitrogen, creatinine, uric acid, calcium, phosphorus and enzymes SGOT or SGPT. However, the alkaline phosphatase showed a gradual decline. The serum iron levels dropped markedly and remained low to the last day of observations (post-infection day, PID 13). On serum protein electrophoresis, the albumin showed a gradual decrease; whereas, alpha II, beta and gamma globulin levels rose suggesting an immune response. The elevation of rectal temperatures and white blood cell counts related well with clinical observations. The serum iron levels proved very helpful in predicting the severity of clinical signs and often dropped before the onset of clinical signs and pyrexia.

Clearance of penicillin G in the newborn calf

Sodium penicillin G was administered intravenously (4545 IU/kg) to calves on the day of birth (12-24 h old) and at 5, 10, and 15 days of age. Serum was collected at varying intervals for 120 min after injection and analysed for penicillin G. The mean total body clearance (ClB) of penicillin G on the day of birth was 2.98 ml/min/kg compared to 4.83 ml/min/kg at 5 days, 3.11 ml/min/kg at 10 days and 4.65 ml/min/kg at 15 days of age. Clearances at 5 and 15 days were significantly (P less than or equal to 0.05) higher than on the day of birth. The half-life (t1/2 beta), however, did not change significantly over the 15-day period of the study. These results indicate that the newborn calf has an appreciable ability to excrete penicillin G before it is 24 h old, and that total body clearance of the antibiotic increases rapidly in the immediate postnatal period.

Experimental Pseudomonas aeruginosa ulcerative keratitis model in the dog

Primary Pseudomonas aeruginosa ulcerative keratitis and accompanying secondary ocular disease were induced bilaterally in 12 of 12 dogs subjected to corneal trephination and intrastromal inoculation. Successful experimental infection was based on recovery of viable Pseudomonas organisms from the lesions, as well as gross and biomicroscopic appearance of the corneas.

Further improvement of the enzyme-linked antiglobulin test (ELAT) for erythrocyte antibodies

The enzyme-linked antiglobulin test (ELAT) was found to be nine times more sensitive than the direct antiglobulin test (DAT) in detecting erythrocytes sensitized by IgG antibody in vitro. The release of hemoglobin and other interfering substances from the erythrocytes gave falsely high absorbance values which were corrected by the use of a hemolysis bland with each test. ELAT results showed good precision. With the use of the hemolysis blank, the ELAT should prove to be a useful tool for hospital blood blanks in the detection of weakly reactive allo- and autoantibodies.

A study on renal function in the Indian buffalo (Bubalus bubalis)

Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) in buffalo species (Bubalus bubalis) were estimated using a single injection technique. The total body clearances of inulin and para-aminohippuric acid (PAH) served as estimates of GFR and ERPF, respectively. Inulin and PAH were administered to animals as a single i.v. bolus. The time-concentration curves were determined for each compound. Three mathematical models were applied to the data. The two compartment model gave the best fit to the data. The single compartment model gave slightly higher values, but could be used in clinical and certain research situations to estimate renal functions when it is not practical to take large number of samples.

Trimethoprim and sulfadiazine: experimental infection of Beagles

The purpose in the present study was to determine whether the commercial combination of trimethoprim (TMP) and sulfadiazine (SDZ) tribrissen (TRI) was more effective than either of the components for treating experimentally induced infection of Streptococcus zooepidemicus. Two dose levels of each were given subcutaneously for treatment, and their effectiveness was compared with that of sulfadimethoxine (SDM) in terms of (i) clinical manifestations, (ii) hematologic changes, (iii) blood culture examinations, and (iv) tissue culture examinations. According to these four measurements, the combination TMP/SDZ was more effective than either of the components. This effect was observed at the two dosages of TRI (30 and 15 mg/kg). The higher dosage, however, was more effective as demonstrated by three of the measurements. Alone, TMP and SDZ were not effective, but SDM treatment was effective in this model.

Statistical considerations in clinical field evaluation of drugs

Statistical problems associated with clinical field evaluation of drugs are many. The Food and Drug Administration requires that the safety and efficacy of a drug must be shown in adequate and well-controlled clinical investigations. From a statistical point of view, safety and efficacy must be precisely defined, and a quantitative method must be developed to measure these properties. It is proposed that efficacy be defined in both the therapeutic and pharmacologic aspects. Further, to measure therapeutic efficacy, it is suggested that an appropriate health index be used. This index would provide information regarding degree of improvement and also the time course of improvement. To measure or evaluate pharmacologic efficacy, it is suggested that kinetic studies be done to compare half-lives, volumes of distribution, and any other relevant kinetic parameter(s).

Interaction of phenytoin with chloramphenicol or pentobarbital in the dog

Two dogs that had been given phenytoin for control of seizures for approximately 1 year developed signs of phenytoin toxicosis (postural ataxia an d a hypermetric gait) when chloramphenicol was added to the therapeutic regimen. The signs of toxicosis disappeared within 24 hours after cessation of chloramphenicol treatment. Oral treatment of laboratory dogs with chloramphenicol (50 mg/kg, TID for 3 days) prior to intravenous injection of phenytoin increased the half-life of phenytoin from 3 hours to 15 hours. Dogs infused with phenytoin during pentobarbital anesthesia had little or no change in serum phenytoin concentration during a 2-hour postinfusion observation period, which was unexpected for the intravenous route of administration.

Ventricular wall thickness in the fetal dog

Ventricular wall thickness of 21 50-to 60-day canine fetuses was determined by direct measurement with calipers. Measurements were made of the left and right ventricular walls and of the interventricular septum, perpendicular to the apico-basilar axis at the location just below the aortic valve, and midway between the coronary sulcus and the apex. Mean determiniations were used to characterize the wall thickne-s at the various levels. The right wall was found to be thickpreciable thickness differences between the septal and left wall at this location. At the level of the midventricular wall, the septal wall thickness exceeded that of the left and right wall. Left and right wall thickness at this level were similar.

Relationship between serum and brain concentrations of phenytoin in the dog

The concentrations of phenytoin (DPH) in the CNS of adult dogs given the drug by IV injection, continuous IV infusion, or repeated daily oral administration and of newborn pups given DPH by IV injection were consistently proportional to serum concentrations of the drug at the time of blood sample collections. Adult dogs injected IV with [14C]DPH failed to show predilection of the drug for the 13 anatomic brain sections sampled. The pharmacokinetics of DPH were studied in adult and neonatal dogs given 15 mg of the drug/kg of body weight as a single IV injection. The mean half-life of the drug in adult dogs injected IV was 4.5 hours. The serum half-life of injected DPH was lowest in pups 30 days of age when compared with that in other age groups. The serum half-life of injected DPH was increased in adult dogs under pentobarbital anesthesia.

Pharmacokinetics and dosage of oxytetracycline in dogs

The pharmacokinetics of oxytetracycline, which was given as a single intravenous dose (5 mg/kg), was studied in normal beagle dogs. Renal function was evaluated by the single injection technique and based on clearance of the radioiodine compounds 125I-iothalamate and 131I-iodohippurate. Values of GFR (4.42+/-0.77 ml/kg/min) and ERPF (12.91+/-1.49 ml/kg/min) showed normal renal function. The disposition curve describing decline of oxytetracycline activity in serum was described mathematically by a triexponential expression. Body clearance was 4.23+/-1.29 ml/kg/min. A dosage regimen (intravenous route of drug administration), based on overall elimincation rate constant (0.1155 h-1) and apparent specific volume of distribution (2 litre/kg), and consisting of a priming dose (10 mg/kg) followed by maintenance doses (7.5 mg/kg) at 12 h intervals was proposed. This dosage regimen was predicted to rapidly achieve and maintain steady state serum concentrations within the range 1.25 to 5.0 microgram/ml, which is therapeutic level for the majority of susceptible microorganisms.