Unintentional non-adherence to chronic prescription medications: how unintentional is it really?

BACKGROUND: Unintentional non-adherence has been characterized as passively inconsistent medication-taking behavior (forgetfulness or carelessness). Our objectives were to: (1) study the prevalence and predictors of unintentional non-adherence; and (2) explore the interrelationship between intentional and unintentional non-adherence in relation to patients' medication beliefs. METHODS: We conducted a cross-sectional survey of adults with asthma, hypertension, diabetes, hyperlipidemia, osteoporosis, or depression from the Harris Interactive Chronic Illness Panel. The analytic sample for this study included 24,017 adults who self-identified themselves as persistent to prescription medications for their index disease. They answered three questions on unintentional non-adherence (forgot, ran out, being careless), 11 questions on intentional non-adherence, and three multi-item scales assessing perceived need for medication (k = 10), perceived medication concerns (k = 6), and perceived medication affordability (k = 4). Logistic regression was used to model predictors of each unintentional non-adherence behavior. Baron and Kenny's regression approach was used to test the mediational effect of unintentional non-adherence on the relationship between medication beliefs and intentional non-adherence. Bootstrapping was employed to confirm the statistical significance of these results. RESULTS: For the index disease, 62% forgot to take a medication, 37% had run out of the medication, and 23% were careless about taking the medication. Common multivariate predictors (p < .001) of the three behaviors were: (1) lower perceived need for medications; (2) more medication affordability problems; (3) worse self-rated health; (4) diabetes or osteoporosis (relative to hypertension); and (5) younger age. Unique statistically-significant predictors of the three behaviors were: (a) 'forgot to take medications' - greater concerns about the index medication and male gender; (b) 'run out of medications' - non-white race, asthma, and higher number of total prescription medications; (c) 'being careless' - greater medication concerns. Mediational tests confirmed the hypothesis that the effect of medication beliefs (perceived need, concerns, and affordability) on intentional non-adherence is mediated through unintentional non-adherence. CONCLUSIONS: For our study sample, unintentional non-adherence does not appear to be random and is predicted by medication beliefs, chronic disease, and sociodemographics. The data suggests that the importance of unintentional non-adherence may lie in its potential prognostic significance for future intentional non-adherence. Health care providers may consider routinely inquiring about unintentional non-adherence in order to proactively address patients' suboptimal medication beliefs before they choose to discontinue therapy all together.

Survey nonresponders to a medication-beliefs survey have worse adherence and persistence to chronic medications compared with survey responders.

OBJECTIVE: The primary objective of this study was to investigate whether nonresponders to a medication-beliefs survey exhibited different adherence and persistence patterns than survey responders. METHODS: A medication-beliefs survey was mailed to 7795 adults aged from 40 to 88 years, who filled a qualifying index prescription (cardiovascular, dyslipidemia, oral-antihyperglycemic, oral-bisphosphonate, and asthma-controller medications) in June 2008 at 1 national and 2 regional retail pharmacies. Adherence and persistence to the index drug class was measured using pharmacy-claims data over 12 months. A multivariate generalized linear model with a negative binomial distribution and log-link function was used to determine whether response status was a significant predictor of adherence. Kaplan-Meier estimates of survival curves were used to assess the time to discontinuation (persistence). Differences between nonresponders and responders were assessed using the log-rank test. RESULTS: The survey response rate was 24.25%. The final analytic sample size after exclusions was 6740 patients (5044 nonresponders and 1696 responders). On the basis of multivariate generalized linear model analysis, survey nonresponders had 11% lower medication adherence compared with responders (P < 0.01; goodness-of-fit=1.09 as defined by deviance/df statistics). The proportion of nonresponders deemed nonpersistent at day 305 was 66.3% compared with 58.1% of responders (P < 0.001). The Kaplan-Meier persistence curves were significantly different for nonresponders and responders as assessed by the log-rank test (χ statistic=49.38; P < 0.001). CONCLUSIONS: Our study found that the responders and nonresponders to a medication-beliefs survey differed significantly in their subsequent adherence and persistence, suggesting that biased survey results are likely to accompany low response rates in surveys of medication use. The use of modest monetary incentives had a small effect on survey response; multiple survey levers are recommended to reduce nonresponse and the potential for biased results.

Individual patients hold different beliefs to prescription medications to which they persist vs nonpersist and persist vs nonfulfill.

OBJECTIVE: Our objective was to explore whether adults hold different beliefs about medications to which they persist vs nonpersist and persist vs nonfulfull. METHODS: We conducted a cross-sectional survey of adults with asthma, hypertension, diabetes, hyperlipidemia, osteoporosis, or other cardiovascular disease from the Harris Interactive Chronic Illness Panel. A quota was set to obtain a sample of respondents who were persistent to a medication for one disease and nonpersistent or nonfulfilling to a medication for a second, different disease. Respondents completed 32 items yielding five multi-item scales: perceived need for medication (k = 12), side-effect concerns (k = 5), medication-safety concerns (k = 5), perceived disease severity (k = 3), and knowledge about the prescribed medication (k = 7). Respondents completed the 32 items twice - once for their persistent medication and a second time for their nonpersistent or nonfulfilling medication. Paired sample t-tests (bivariate) and generalized estimating equations (GEE) models (multivariate) were used to test the study hypotheses. RESULTS: Overall, 178 respondents were sampled for being persistent to one medication and nonpersistent to another, while 48 respondents were persistent to one medication and nonfulfilling to a second. For the medication to which an individual patient was persistent vs nonpersistent, there was significantly higher perceived need, fewer side-effect concerns, higher perceived disease severity, and better knowledge about the medication. For the medication to which an individual patient was persistent vs nonfulfilling, there was significantly higher perceived need, fewer side-effect concerns, and better knowledge about the medication. CONCLUSION: Individual patients hold different beliefs about medications to which they persist vs nonpersist or nonfulfill. Patients exhibit different medication-taking behaviors for different medications because they weigh the perceived risks and benefits for each medication separately. These results suggest that adherence interventions should be tailored to patients' beliefs about specific medications.

Effects of Medicare Part D on drug affordability and use: Are seniors with prior high out-of-pocket drug spending affected more?

BACKGROUND: Medicare Part D was expected to have differential impacts on patient drug expenditures and use based on beneficiaries' levels of pre-Part D patient drug spending, but it is unknown whether these projections have borne out. OBJECTIVES: We sought to evaluate whether and how the policy effect of Medicare Part D on drug expenditures and use was modified by levels of pre-Part D drug spending. METHODS: A quasi-experimental, pretest-posttest, nonequivalent control group design was used. Data were obtained from a regional supermarket chain for all prescriptions dispensed between January 1, 2005, and December 31, 2007 (n=1,230,612) to patients aged 60 years and older as of January 1, 2005 (n=51,305) to construct 12-month pre-Part D and post-Part D periods. Annual medication use was measured as the total number of pill days acquired. Annual drug expenditures were measured as total expenditures, patient out-of-pocket expenditures, and the proportion of total expenditures paid out of pocket by the patient. RESULTS: Part D resulted in significant reductions in out-of-pocket spending (17.6%) and significant increases in drug use (4.0%) for individuals in the highest pre-Part D drug-spending group relative to controls. The reduction in out-of-pocket spending for the highest pre-part D spending group was significantly greater compared with the moderate and lowest pre-Part D spending groups. CONCLUSIONS: Our findings suggest that, as expected, Part D facilitated access to medications for patients who previously experienced the greatest costs without adversely increasing use and costs among those with the lowest prior cost.

Medication nonfulfillment rates and reasons: narrative systematic review.

BACKGROUND: The literature on nonfulfillment of prescription medications spans over three decades of work. There is a wide variation in reported nonfulfillment rates, but no previous study has systematically reviewed this literature to explore the reasons behind this variation. OBJECTIVE: The objective of this study was to review estimates of medication nonfulfillment rates and published reasons for nonfulfillment and explore whether nonfulfillment rates vary by study variables. METHODS: Articles were identified through searches conducted on MEDLINE, CINAHL, Psych Info, and EMBASE, and review of relevant reference citations. Methodological variables, nonfulfillment rate, and unit of analysis (i.e., patient or prescription) were abstracted from each article selected for review. Mean and median nonfulfillment rates for groups categorized by unit of analysis and selected methodological variables (method for assessing nonfulfillment, sample characteristics, disease subgroup, sample size, country of data collection, recall period or time allowed before classifying as nonfulfillment, and year of study) were calculated. Reasons for nonfulfillment were abstracted from all articles that included a relevant discussion. FINDINGS: A total of 79 studies reporting pure nonfulfillment rates (59 at the patient level and 20 at the prescription level) and six studies reporting nonfulfillment rates in combination with nonpersistence rates were included. There was a wide variation in nonfulfillment rates reported by the studies - from 0.5% to 57.1%. The three primary reasons for nonfulfillment identified from this review were perceived concerns about medications, lack of perceived need for medications, and medication affordability issues. CONCLUSION: To the best of the authors' knowledge, this study is the first narrative systematic review on nonfulfillment of prescription medications. Despite the wide variation in individual study rates, the mean and median rates across different modes of data collection and sources of data were in a relatively narrow range (11% to 19%) and surprisingly close to the overall mean (16.4%) and median (15%.0) rates for all studies. The reasons for nonfulfillment identified through this review address barriers to nonfulfillment at the patient, physician, and health system level and thus bear important implications for policy makers.

Pharmacy characteristics associated with the provision of drug therapy services in nonmetropolitan community pharmacies.

CONTEXT: Higher prevalence of chronic diseases and reduced access to other health professionals in rural areas suggest that rural Medicare enrollees will benefit from pharmacist-provided drug therapy services (DTS). PURPOSE: The purpose of this study was to describe non-metropolitan community pharmacy sites in Wisconsin, the provision of DTS at these sites, and to identify factors associated with provision of DTS. METHODS: A cross-sectional, descriptive survey design was used to collect primary data in 2005. The manager/owner listed for each of the 279 non-metropolitan community pharmacy sites in Wisconsin was surveyed using an 8-page instrument. The 7 drug therapy services that key informants were asked to report on included 6 disease state management (DSM) programs and medication therapy management services (MTMS). Descriptive statistics were calculated for variables describing the pharmacy sites and how DTS were provided. Logistic regression was performed, with any drug therapy service provision as the dependent variable and 8 independent variables. FINDINGS: The response rate to the survey was 44%. Overall, 31% of the respondent pharmacies offered MTMS and 31% offered DSM programs. Higher service orientation, location in a more rural area, and lower workload per pharmacist were significantly positively related to provision of any DTS. CONCLUSIONS: Conducted 4 months prior to the implementation of Medicare Part D, the results serve as a baseline against which the effects of Part D on MTMS provision may be evaluated. The negative association of pharmacist workload with pharmacy provision of DTS, coupled with the current pharmacist shortage, has important implications for patients' access to these services in rural areas.

Characteristics of unmet demand for pharmacists: a survey of rural community pharmacies in Wisconsin.

OBJECTIVES: To measure and describe the level of unmet demand for pharmacists in rural Wisconsin community pharmacies and to examine determinants of the level of unmet demand in these pharmacies. DESIGN: Cross-sectional descriptive study. SETTING: Community pharmacies (n = 279) located in rural Wisconsin counties in fall 2005. PARTICIPANTS: Key informants (managers/owners) identified for all sampled pharmacies. INTERVENTIONS: A one-page participation form and an eight-page survey instrument were used to collect primary data about the level of unmet demand for pharmacists and internal pharmacy factors. Secondary data sources were used to extract information on external pharmacy factors. MAIN OUTCOME MEASURES: Presence of pharmacist vacancy, number of full-time equivalent (FTE) pharmacist positions vacant, and vacancy rate. Internal pharmacy characteristics included wage, prescription volume, prescription workload/pharmacist, dispensing-aiding technologies, technicians per pharmacist, practice setting, pharmacist FTE requirement, and pharmacist satisfaction. External pharmacy characteristics included population per pharmacy, seniors per pharmacy, per capita income, and rurality. The internal and external pharmacy characteristics were regressed on whether a vacancy was present and the vacancy rate (percentage of pharmacist FTEs unfilled). RESULTS: Overall response rate to the survey was 43.9%. One-third of the respondent pharmacy sites reported a pharmacist vacancy, most often 1.0 or less FTE. Pharmacist FTE requirement had a significant positive association with the presence of any pharmacist vacancy at a site. Prescription workload per pharmacist was positively related to the vacancy rate, while daily prescription volume and pharmacist satisfaction were negatively related to the vacancy rate. CONCLUSION: Overall, for rural community pharmacies in Wisconsin, a greater need for pharmacists at a site appears to make that site more likely to have a pharmacist vacancy. Pharmacist vacancies appear to have a greater impact on pharmacies that have a lower number of FTE pharmacist positions compared with pharmacies with higher FTE pharmacists because, potentially, fewer pharmacists are present to redistribute the workload.