Abigail Cohen

Risk factors for nonadherence to warfarin: results from the IN-RANGE study†‡

Warfarin is widely used to prevent stroke and venous thromboembolism despite its narrow therapeutic window. Warfarin nonadherence is a substantial problem, but risk factors have not been well elucidated.

Medication Safety in Older Adults: Home‐Based Practice Patterns

Objectives: To identify the current state of medication‐taking practices of community‐dwelling older adults on high‐risk medications.

A systematic review of psychosocial interventions to improve cancer caregiver quality of life

To evaluate and estimate the effect of psychosocial interventions on improving the quality of life (QoL) of adult cancer caregivers.

Psychosocial factors associated with the stages of change for condom use among women at risk for HIV and STDs: implications for intervention development.

This study examined the prevalence of consistent condom use among inner-city women at risk for HIV, measured the distribution of these women across the stages of change for condom use, determined psychosocial factors associated with the stages, and suggested intervention strategies based on the results. The 5-city sample of women aged 15-34 years consisted predominantly of African Americans. Only 18% reported consistent condom use with main partners and 45% with other partners. Logistic regressions compared women in each stage of change with those in higher stages for each partner type. Results indicated that women who practice or intend to practice consistent condom use were more likely to talk with others about condoms, acknowledge the advantages of condoms, have higher self-efficacy for condom use, and indicate that people important to them favored condom use. Intervention approaches are suggested for women in different stages of change for condom use.

Can We Predict Daily Adherence to Warfarin?: Results From the International Normalized Ratio Adherence and Genetics (IN-RANGE) Study

BACKGROUND Warfarin is the primary therapy to prevent stroke and venous thromboembolism. Significant periods of nonadherence frequently go unreported by patients and undetected by providers. Currently, no comprehensive screening tool exists to help providers assess the risk of nonadherence at the time of initiation of warfarin therapy. METHODS This article reports on a prospective cohort study of adults initiating warfarin therapy at two anticoagulation clinics (university- and Veterans Affairs-affiliated). Nonadherence, defined by failure to record a correct daily pill bottle opening, was measured daily by electronic pill cap monitoring. A multivariable logistic regression model was used to develop a point system to predict daily nonadherence to warfarin. RESULTS We followed 114 subjects for a median of 141 days. Median nonadherence of the participants was 14.4% (interquartile range [IQR], 5.8-33.8). A point system, based on nine demographic, clinical, and psychosocial factors, distinguished those demonstrating low vs high levels of nonadherence: four points or fewer, median nonadherence 5.8% (IQR, 2.3-14.1); five points, 9.1% (IQR, 5.9-28.6); six points, 14.5% (IQR, 7.1-24.1); seven points, 14.7% (IQR, 7.0-34.7); and eight points or more, 29.3% (IQR, 15.5-41.9). The model produces a c-statistic of 0.66 (95% CI, 0.61-0.71), suggesting modest discriminating ability to predict day-level warfarin nonadherence. CONCLUSIONS Poor adherence to warfarin is common. A screening tool based on nine demographic, clinical, and psychosocial factors, if further validated in other patient populations, may help to identify groups of patients at lower risk for nonadherence so that intensified efforts at increased monitoring and intervention can be focused on higher-risk patients.

Identifying and Quantifying Medication Errors: Evaluation of Rapidly Discontinued Medication Orders Submitted to a Computerized Physician Order Entry System

All methods of identifying medication prescribing errors are fraught with inaccuracies and systematic bias. A systematic, efficient, and inexpensive way of measuring and quantifying prescribing errors would be a useful step for reducing them. We ask if rapid discontinuations of prescription-orders--where physicians stop their orders within 2 hours--would be an expedient proxy for prescribing errors? To study this we analyzed CPOE-system medication orders entered and then discontinued within 2 hours. We investigated these phenomena in real time via interviews with corresponding ordering physicians. Each order was also independently reviewed by a clinical pharmacist or physicians. We found that of 114 rapidly discontinued orders by 75 physicians, two-thirds (35 of 53, PPV = 66; 95% CI = 53-77) of medication orders discontinued within 45 minutes were deemed inappropriate (overdose, underdose, etc.). Overall, 55% (63 of 114; 95% CI = 46-64%) of medication orders discontinued within 2 hours were deemed inappropriate. This measure offers a rapid, constant, inexpensive, and objective method to identify medication orders with a high probability of error. It may also serve as a screening and teaching mechanism for physicians-in-training.

Neither panacea nor black box: responding to three journal of biomedical informatics papers on computerized physician order entry systems

a Department of Sociology and Center for Clinical Epidemiology and Biostatistics of the School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA b Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, Center for Education and Research in Therapeutics, University of Pennsylvania School of Medicine, USA c Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, USA d Department of Biostatistics and Epidemiology, Department of Medicine (General Medicine Division), Department of Pharmacology, Center for Clinical Epidemiology and Biostatistics, Center for Education and Research in Therapeutics, University of Pennsylvania School of Medicine, USA

Hospitalization costs associated with warfarin-related bleeding events among older community-dwelling adults.

A prior paper from this study demonstrated that patient report of receiving medication instructions from health care professionals is associated with reduced risk of warfarin‐related bleeding hospitalizations. The objective of this analysis was to describe the hospitalization costs due to warfarin‐related bleeding events in older community‐dwelling adults and to estimate the hospitalization costs avoided due to the receipt of medication instruction from different sources.

Diagnostic E-codes for commonly used, narrow therapeutic index medications poorly predict adverse drug events

OBJECTIVE We sought to examine the validity of specific hospital discharge codes in identifying drug toxicity precipitating hospitalization, among elderly users of high-risk medications. STUDY DESIGN AND SETTING We conducted a cross-sectional evaluation assessing the diagnostic test characteristics of International Classification of Diseases-9 External-Cause-of-Injury codes (E-codes) compared with a reference standard of medical record review. This study was nested within a prospective cohort of elders using warfarin, digoxin, or phenytoin as identified in the Pharmaceutical Assistance Contract for the Elderly benefit program. RESULTS We identified 4,803 subjects contributing 11,409 person-years of exposure to at least one of three drug groups. Subjects experienced 8,756 hospitalizations, of which 304 were deemed, by expert review, to be a result of an adverse event of warfarin, digoxin, or phenytoin. The sensitivity, specificity, and positive (PPVs) and negative predictive values for drug-specific E-codes were warfarin--25.5%, 98.3%, 46.6%, and 95.7%; digoxin--84.0%, 99.1%, 56.8%, and 99.8%; and phenytoin--86.7%, 98.7%, 59.1%, and 99.7%. CONCLUSIONS E-codes for digoxin and phenytoin have a high sensitivity, but E-codes for all three medications have poor PPVs, a result that might produce misclassification in studies based solely on discharge coding. Investigators should confirm such rare events via medical record review.

Factors associated with perceptions of and decisional balance for condom use with main partner among women at risk for HIV infection.

ABSTRACT We examined factors associated with womens perceived advantages (pros), perceived disadvantages (cons), and decisional balance (standardized pros score minus standardized cons score) for condom use with main partner. Data from 1,938 young sexually active women who lived in five U.S. cities where the risk for human immunodeficiency virus is high were analyzed by using logistic, ordinal, and multiple linear regression analysis. For the pros scale of condom use, 27% of the women had low scores, and 33% had moderate scores. For the cons scale, 27% had moderate scores, and 5% had high scores. Of the total, 47% had a negative score on the decisional balance measure. Older age, living with a spouse or partner, or binge drinking was associated with lower pros scores and with a negative score on the decisional balance measure. Income from public assistance was associated with higher pros scores. Income from a spouse or partner or a history of sexually transmitted disease was associated with lower pros scores. Multiple sex partners or being at risk for HIV infection (based on perceptions of the main partners behaviors) was associated with higher cons scores. Income from a job was associated with a positive score on the decisional balance measure. Our analysis identified the characteristics of women who have low pros scores, high cons scores, and negative decisional balance scores. The regression results can inform our work in HIV prevention on whether to focus on the pros, the cons, or both to obtain positive decisional balance scores and increase condom use in situations that warrant protective behaviors.