Michael B. Nichol

Medication Adherence and Associated Hemoglobin A1c in Type 2 Diabetes

BACKGROUND: Tight blood glucose control has been correlated with a reduction in diabetes complications. Adherence to antidiabetic medications is crucial to achieving blood glucose control. OBJECTIVE: To assess the relationship between good glucose control [glycosylated hemoglobin (HbA1c) levels] and adherence to prescribed treatment in patients on a stable medication regimen for type 2 diabetes. METHODS: The Morisky survey, a 4–item questionnaire that predicts patient medication-taking behavior, was used to assess adherence in 301 patients. The relationship of HbA1c to Morisky score was evaluated, controlling for other variables related to patient demographics and clinical characteristics. Data were analyzed using a general linear model on log (HbA1c). RESULTS: Unadjusted mean HbA1c values (capped at 14.0%) for patients with Morisky scores of 0 or 1, 2, 3, and 4 were 8.92%, 8.67%, 7.74%, and 7.60%, respectively. Of all patients, 13.0%, 14.0%, 24.3%, and 48.8% had scores of 0 or 1, 2, 3, and 4, respectively. Good adherence (Morisky score ≥3) was associated with a 10% lower total HbA1c (p = 0.0003) adjusted for all other factors in the model. Duration of diabetes (5–10 y) and presence of diabetes complications were also significantly associated with HbA1c (p = 0.026 and 0.002, respectively). Adherence was poor in 27% of patients. CONCLUSIONS: This study found that patients with a higher score on the Morisky scale had a lower associated HbA1c measurement. The Morisky score may be an efficient tool for identifying patients with poor medication-taking behavior who can then be targeted for directed adherence counseling services.

The costs of interrupting antihypertensive drug therapy in a Medicaid population.

This research explores the association between the interruption or termination of antihypertensive drug therapy and total health care costs among non-institutionalized Medicaid patients older than age 40 who survive the first year after treatment. Multivariate regression analysis was used to estimate the statistical relationship between post-treatment costs and patient demographic characteristics, prior use of services, the type of medication used as initial therapy and whether the patient maintained continuous therapy. Paid claims data from the California Medicaid (Medi-Cal) program were used in the analysis. Total cost of health care in the first year after the initiation of drug therapy was the primary outcome variable. Components of total costs (e.g., hospital, outpatient and physician services, prescription drugs) were also investigated. Nearly 86% of new antihypertensive drug therapy patients interrupted or discontinued purchasing any form of antihypertensive medication during the first year. Patients with interrupted antihypertensive drug therapy consumed an additional

Evaluating Quality-Adjusted Life Years: Estimation of the Health Utility Index (HUI2) from the SF-36

873 per patient (P < .0001) in health care during the first year, not counting a reduction in prescription drug cost of

A Critical Evaluation of the Methodology of the Literature on Medication Compliance

281 (P < .0001). Increased costs were primarily due to increased hospital expenditures of

Compliance with Sulfonylureas in a Health Maintenance Organization: A Pharmacy Record–Based Study

637 (P < .0002).

The application of multiple quality-of-life instruments in individuals with mild-to-moderate psoriasis.

Quality-adjusted life years (QALYs) are well recognized as a valid measure for outcomes in cost-effectiveness analyses. A summary health utility score is necessary to evaluate QALYs. The objective of this study was to predict a summary utility score (represented by the Health Utility Index [HUI2]) from scores on the SF-36. Methods. A structural equation framework was applied to longitudinal data collected from 1992 to 1995 on a sample of patients insured by Southern California Kaiser Permanente (N= 6921). An ordinary least squares (OLS) method was used to estimate the HUI2. Results. The OLS model on cross-sectional data predicted 50.5% of the observed variance in HUI2 scores. Parameter estimates of all SF-36 components showed statistical significance at the P < 0.05 level. Conclusions. Results of this study provide a quantitative link between two important measures of health status. The present model can be used to estimate health utility summary scores in studies that have collected SF-36 data.

Quality of Anticoagulation Monitoring in Nonvalvular Atrial Fibrillation Patients: Comparison of Anticoagulation Clinic versus Usual Care

OBJECTIVE: To develop a simple evaluation tool to assess methodologic rigor of the literature on patient compliance with medications, and to apply the tool to a sample of the literature. METHODS: A computerized search of the MEDLINE database (January 1980–December 1996) was performed. All English-language articles on compliance with medications were identified, using the MeSH terms patient-compliance and drug-therapy. A 10% sample was then randomly selected for review. Methodologic rigor was assessed on eight standards: study design, specification of patient sample, power analysis, specification of disease, specification of therapeutic regimen, duration of follow-up, definition of compliance, and compliance measurement. The raw scores of the eight standards were then combined in three summary scores, standardized from 0 to 100: study design, disease-related features, and compliance issues. RESULTS: Seventy-two articles from 719 identified were reviewed. The majority of the research articles were descriptive (63.9%), and patients in these studies were selected mainly from a convenience sample (41.7%). Just nine studies were multicenter studies, and three employed power analysis. The compliance definition was replicable in 41.7% of the studies. In 22 articles neither the compliance measure nor the criteria were stated. One-quarter of the studies (18) used a nonvalidated measure of compliance. Only two studies reached a score of 6 in the compliance measure, and eight studies used two different measures of compliance simultaneously. The median values in the summary scores were: study design 8.3, disease 42.9, compliance issues 50. CONCLUSIONS: The quality of the compliance research was generally poor. These low scores reflect very important shortcomings in the methodology. Such oversights make it difficult for the reader to critically assess the validity of the conclusions.

Mapping the SF-12 to the HUI3 and VAS in a managed care population

OBJECTIVE: To determine which factors affect compliance with sulfonylureas in a population served by a health maintenance organization in Southern California. METHODS: Retrospective analysis of pharmacy records and healthcare utilization data for two years (April 1993–March 1995), and a survey mailed to patients. Patients treated with sulfonylureas were selected for analysis on the basis of their prescription profile. Compliance was measured from the pharmacy records as the proportion of days the patient was in possession of the prescribed medications. Patient compliance with sulfonylureas was modeled as a function of four clusters of determinants: patient-related attributes, drug regimen characteristics and complexity, health status and disease-related variables, and characteristics of the interaction with healthcare providers. RESULTS: 786 patients were identified for analysis (49.1% women, mean age 59 y). The mean compliance rate was 83% ± 22% SD. Compliance was significantly positively related with age and self-reported level of medication-taking compliance at baseline. Factors shown to have an inverse relationship with compliance were treatment complexity, perception of general health, and being a newly treated patient (adjusted R2 for the final model = 0.148). CONCLUSIONS: Our results suggest that factors found to be associated with noncompliant behavior (e.g., being a newly treated patient, self-reported compliance, regimen complexity) can be assessed by physicians and pharmacists as a routine practice.

Evaluating Use Patterns of and Adherence to Medications for Benign Prostatic Hyperplasia

The 36-item Short-Form Health Survey Questionnaire (HSQ SF-36), Psoriasis Disability Index (PDI), and Dermatology Life Quality Index (DLQI) were administered to individuals with mild-to-moderate psoriasis to validate the general quality-of-life instrument against the dermatosis-specific, and the dermatology-specific, disability measure. The population consisted of 644 adults with psoriasis involving up to 20% of the body surface area, who were enrolled in 2 US multicentre, evaluator-blinded, parallel-group clinical trials for a new psoriasis medication. Patients averaged 16.5% of maximum possible disability as measured by the PDI, and 23.4% of maximum possible disability as measured by the DLQI. Normalised T-scores showed that the patients approximated US population means on all 8 of the HSQ SF-36 dimensions. The HSQ SF-36 scales did not reflect substantial quality-of-life impairment, although all showed statistically significant correlations with both the PDI and DLQI (correlation coefficients ranging from -0.13 to -0.45). Moreover, while the disability indices were more responsive to psoriasis characteristics than the HSQ SF-36 quality-of-life scales, all 8 HSQ SF-36 dimensions demonstrated sensitivity to at least some objective and/or subjective ratings of severity. The strongest relationships were observed between the PDI, DLQI and the HSQ SF-36 Mental Health and Social Functioning dimensions, suggesting that the HSQ SF-36 is sensitive to psychosocial suffering related to psoriasis, which is not conveyed in objective clinical measures of severity.

A cost and performance evaluation of disposable and reusable biopsy forceps in GI endoscopy

Background: Prior research suggests that receiving specialized anticoagulation services enables patients to achieve better clinical outcomes. Objective: To assess the quality of anticoagulation therapy in patents with atrial fibrillation who were enrolled in an anticoagulation clinic (ACC) versus usual care (UC). Methods: Using Sharp Rees-Stealy physician group claims data, we estimated time spent in therapeutic range and time to first major bleeding episode or stroke for ACC and UC patients. t-Tests were used to compare time h therapeutic range proportions, and Kaplan-Meier survival analysis was performed to compare rates of bleeding and stroke between groups. Results: We identified 1107 patients (351 ACC, 756 UC) treated with anticoagulation therapy for atrial fibrillation with more than one international normalized ratio (INR) reported between March 2001 and March 2004. ACC patients spent a greater proportion (68.14%) of time in therapeutic range compared with UC patients (42.07%; p < 0.001). There was a significant difference between groups in average time between INR tests (ACC = 14.31 days, UC = 18.39 days; p < 0.001). ACC patients were 59% less likely to experience a bleed following the index date than were UC patients (HR = 0.41; 95% CI 0.2444 to 0.6999; p = 0.001), but type of care was not a significant predictor for stroke (HR = 0.95; 95% CI 0.5125 to 1.7777; p value NS). Conclusions: Results from this observational study reinforce the positive impact that anticoagulation services have on anticoagulation therapy outcomes, emphasizing the importance of providing such services for patients undergoing treatment with warfarin.