Clinical outcomes and adherence to medications measured by claims data in patients with diabetes

Relationships among self-management, patient perceptions of care, and health economic outcomes for decision-making and clinical practice in type 2 diabetes

OBJECTIVES

Type 2 diabetes (T2D) treatment involves complex interactions between biological, psychological, and behavioral factors of care, requiring multifaceted efforts in clinical practice and disease management to reduce health and economic burdens. We aimed to quantify correlations among these factors and characterize their level of inclusion in economic analyses that are part of informed medical decision-making.

METHODS

A comprehensive, stepwise systematic literature review was performed on published articles dated 1993 to 2008 using medical subject heading and keyword searches in electronic reference libraries. Data were collected using standardized techniques and were analyzed descriptively.

RESULTS

A total of 97 articles fulfilling all inclusion criteria were reviewed, including 16 on economic models (17% of articles). Most studies were retrospective (41 of 97; 42%) and from managed care perspectives (66%). Oral antidiabetic drugs were a central focus, appearing in 83% of studies. Patient behaviors, particularly medication adherence and persistence in real-world settings, are well researched (n=65) and may influence diabetes outcomes, cardiovascular risk, mortality rates, and treatment-specific resource use (e.g., hospitalizations) and costs (<or=$3400 annually per patient). Nevertheless, they are absent from current economic models.

CONCLUSIONS

Strong correlations exist between patient behaviors, perspectives of care, health outcomes, and costs in T2D. Enhancing their inclusion in pharmacoeconomic modeling, notably the influence on clinical effectiveness of variation in self-management between treatments, should ultimately lead to more accurate estimates of comparative cost-effectiveness, and thereby improve value-based resource allocation and patient access to appropriate therapy.

A comparison of diabetes medication adherence and healthcare costs in patients using mail order pharmacy and retail pharmacy

OBJECTIVE

To compare long-term diabetes medication adherence and healthcare costs in patients using mail order pharmacy versus retail pharmacy.

METHODS

The MarketScan database was used to identify patients who filled prescriptions for oral anti-diabetes medications in a retail pharmacy for at least 6 months before switching to mail order pharmacy for at least 12 months. These patients were matched to others who used retail pharmacy continuously for at least 18 months. A propensity score was used to create matched groups of patients comparable on probability of switching to mail order, weighted Poisson regression was used to analyze differences in medication adherence, and Tobit regression was used to compare costs.

RESULTS

A total of 14,600 patients who switched to mail order were matched to 43,800 patients who used retail pharmacy continuously. The average adjusted adherence in retail pharmacy was 63.4% compared to 84.8% after switching to mail order. Per-member-per-month total healthcare and total medical costs were on average $34.32 and $37.54 lower in the mail order group, respectively. Diabetes-related medical costs were on average $19.14 lower in the mail order group, while pharmacy costs were $14.13 higher.

LIMITATIONS

Limitations include a patient population under the age of 65, no information on pharmacy benefit design, and limited follow-up time relative to that necessary to identify long-term diabetes complications.

CONCLUSIONS

After adjusting for measured confounders of medication adherence and disease severity, individuals who switched to mail order pharmacy had higher medication possession ratios and trended toward lower total and diabetes-related medical costs over time.

The role of cognitive impairment and caregiver support in diabetes management of older outpatients

OBJECTIVES

To examine the role of cognitive impairment and caregiver support in diabetes care adherence and glycemic control.

METHODS

Fifty-one veteran male outpatients (27 with caregivers) aged 60 years and older with type 2 diabetes were evaluated for cognitive impairment with the Cognitive Abilities Screening Instrument. Patients or caregivers completed diabetes self-care and depression scales. Medical morbidity information and HbA1c plasma levels at baseline and 1 year later were obtained from electronic medical records.

RESULTS

Greater cognitive impairment (F = 5.1, p < .05), and presence of a caregiver (F = 5.3, p < .05), were independently associated with worse diabetes care adherence (adjusting for age, education, medical comorbidity, and depression). In addition, Mean HbA1c levels were worse in the cognitively impaired group with caregivers relative to the three other groups (F = 4.10, p < .05, eta2 = .09). One year later, mean HbA1c levels rose from 7.7 to 8.2% in the cognitively impaired group with caregivers.

CONCLUSION

Cognitive impairment is associated with worse diabetes care management. Surprisingly, the presence of a caregiver is not protective. Further research is necessary to examine the healthcare needs of cognitively impaired, diabetic patients and their caregivers.

Clinical inertia in general practice: widespread and related to the outcome of diabetes care

BACKGROUND AND AIMS

Clinical inertia is considered a major barrier to better care. We assessed its prevalence, predictors and associations with the intermediate outcomes of diabetes care.

MATERIALS AND METHODS

Baseline and follow-up data of a Dutch randomized controlled trial on the implementation of a locally adapted guideline were used. The study involved 30 general practices and 1283 patients. Treatment targets differed between study groups [HbA1c <or= 8.0% and blood pressure (BP) < 140/85% versus HbA1c <or= 8.5% and BP < 150/85]. Clinical inertia was defined as the failure to intensify therapy when indicated. A complete medication profile of all participating patients was obtained.

RESULTS

In the intervention and control group, the percentages of patients with poor diabetes or lipid control who did not receive treatment intensification were 45% and 90%, approximately. More control group patients with BP levels above target were confronted with inertia (72.7% versus 63.3%, P < 0.05). In poorly controlled hypertensive patients, inertia was associated with the height of systolic BP at baseline [adjusted odds ratio (OR) 0.98, 95% confidence interval (CI) 0.98-0.99] and the frequency of BP control (adjusted OR 0.89, 95% CI 0.81-0.99). If a practice nurse managed these patients, clinical inertia was less common (adjusted OR 0.12, 95% CI 0.02-0.91). In both study groups, cholesterol decreased significantly more in patients who received proper treatment intensification.

CONCLUSION

GPs were more inclined to control blood glucose levels than BP or cholesterol levels. Inertia in response to poorly controlled high BP was less common if nurses assisted GPs.

Diabetes and poor disease control: is comorbid depression associated with poor medication adherence or lack of treatment intensification?

OBJECTIVE

To hypothesize that patients with comorbid depression and diabetes and poor disease control will have poorer adherence to disease control medication and less likelihood of physician intensification of treatment. Many patients with diabetes fail to achieve American Diabetes Association Guidelines for glycemic, blood pressure and lipid control. Depression is a common comorbidity and may affect disease control through adverse effects on adherence and physician intensification of treatment.

METHODS

In a cohort of 4117 patients with diabetes, depression was measured at baseline with the Patient Health Questionnaire-9 (PHQ-9). Patient adherence and physician intensification of treatment were measured in those who had evidence of poor disease control (HbA(1c) >or=8.0%, LDL >or=130 mg/dL, systolic blood pressure >or=140 mm Hg) over this 5-year period. Poor adherence was defined as having medication refill gaps for >or=20% of days covered for medications prescribed for each of these conditions. Treatment intensification was defined as an increased medication dosage in a class, an increase in the number of medication classes, or a switch to a different class within 3-month periods before and after notation of above target levels.

RESULTS

Among patients with diabetes and poor disease control, depression was associated with an increased likelihood of poor adherence to diabetes control medications (odds ratio [OR] = 1.98; 95% Confidence Interval [CI] = 1.31, 2.98), antihypertensives (OR = 2.06; 95% CI = 1.47, 2.88), and LDL control medications (OR = 2.43; 95% CI = 1.19, 4.97). In patients with poor disease control who were adherent to medication or not yet started on a medication, depression was not associated with differences in likelihood of physician intensification of treatment.

CONCLUSIONS

In patients with diabetes and poor disease control, depression is an important risk factor for poor patient adherence to medications, but not lack of treatment intensification by physicians.

Diabetes Health Coaching Improves Medication Adherence: A Pilot Study

Adherence to medications is central to successfully managing diabetes. Health coaching, which relies on frequent contact and ongoing intervention, has emerged in recent years as part of disease management initiatives and has been promoted as an effective method for improving health outcomes and patient compliance with medication. This study evaluated a 6-month worksite health coaching model to promote medication adherence. It assessed the effectiveness of tailoring health coaching for compliance with medication regimens among people with diabetes. The program was delivered through 3 face-to-face and 3 telephone consultations. Participants set goals promoting diabetes management at the end of each monthly consultation. The authors collected questionnaires from enrolled employees at baseline (n = 27) and from those who stayed in the program at completion of the intervention (n = 23). Using the ASK-20 SM for evaluation, the authors were able to significantly reduce the average number of barriers to medication adherence from pre (3.7) to post (2.2; P < .001) in those who completed the program. The results of this study suggest that health coaching combined with tools to help identify barriers increased medication adherence.

Derivation and validation of the ASK-12 adherence barrier survey

BACKGROUND

The ASK-20 survey is a previously validated patient-report measure of barriers to medication adherence and adherence-related behavior.

OBJECTIVE

To derive and validate a shorter version of the ASK-20 scale.

METHODS

Patients with asthma, diabetes, and congestive heart failure were recruited from a university medical center. Participants completed the ASK-20 survey and other questionnaires. Approximately one-third of participants were randomized to a 2-week retest administration. Item performance and results of an exploratory factor analysis were examined for item reduction and subscale identification. Subsequent analyses examined reliability and validity of the shorter version of the ASK.

RESULTS

A total of 112 patients participated (75.9% female; mean age 46.7 y; 53.6% African American). Eight items were dropped from the ASK-20 based on factor loadings, floor effects, Cronbach's alpha, and the ability of each item to discriminate between groups of patients differing in self-reported adherence. The new total score (ASK-12) had good internal consistency reliability (Cronbach's alpha 0.75) and test-retest reliability (intraclass correlation 0.79). Convergent validity was demonstrated through correlations with the Morisky Medication Adherence Scale (r -0.74; p < 0.001), condition-specific measures, the SF-12 Mental Component Score (r -0.32; p < 0.01), and proportion of days covered by filled medication prescriptions in the past 6 months as indicated by pharmacy claims data (r -0.20; p = 0.059). The ASK-12 total score also discriminated among groups of patients who differed in self-reported adherence indicators, including whether a dose was missed in the past week, the number of days medication was not taken as directed, and treatment satisfaction. Three subscales were identified (adherence behavior, health beliefs, inconvenience/forgetfulness), and results provided initial support for their validity.

CONCLUSIONS

The ASK-12 demonstrated adequate reliability and validity, and it may be a useful brief measure of adherence behavior and barriers to treatment adherence.

Relationship between thiazolidinedione use and cardiovascular outcomes and all-cause mortality among patients with diabetes: a time-updated propensity analysis

PURPOSE

To investigate the association of the thiazolidinediones (TZDs), rosiglitazone, and pioglitazone, together and individually on the risk of cardiovascular outcomes and all-cause mortality, using time-updated propensity score adjusted analysis.

METHODS

We conducted a retrospective cohort study in a large vertically integrated health system in southeast Michigan. Cohort inclusion criteria included adult patients with diabetes treated with oral medications and followed longitudinally within the health system between 1 January 2000 and 1 December 2006. The primary outcome was fatal and non-fatal acute myocardial infarction (AMI). Secondary outcomes included hospitalizations for congestive heart failure (CHF), fatal, and non-fatal cerebrovascular accidents (CVA) and transient ischemic attacks (TIA), combined coronary heart disease (CHD) events, and all-cause mortality.

RESULTS

19,171 patients were included in this study. Use of TZDs (adjusted hazard ratio (aHR) with propensity adjustment (PA), 0.92; 95% confidence interval (CI) 0.73-1.17), rosiglitazone (aHR with PA, 1.06; 95%CI 0.66-1.70), and pioglitazone (aHR with PA, 0.91; 95%CI 0.69-1.21) was not associated with a higher risk of AMI. However, pioglitazone use was associated with a reduction in all-cause mortality (aHR with PA, 0.60; 95%CI 0.42-0.96). Compared with rosiglitazone, pioglitazone use was associated with a lower risk of all outcomes assessed, particularly CHF (p = 0.013) and combined CHD events (p = 0.048).

CONCLUSIONS

Our findings suggest that pioglitazone may have a more favorable risk profile when compared to rosiglitazone, arguing against a singular effect for TZDs on cardiovascular outcomes.

Perceptions and attitudes are primary contributors to insulin delivery system satisfaction in people with type 2 diabetes

BACKGROUND

This study identifies factors that influence satisfaction with an insulin delivery system (IDS). Knowledge of such factors could help identify individuals who would benefit from innovative IDS.

METHODS

Individuals with type 2 diabetes who use insulin, recruited from a general and chronic illness panel, participated in a web-based survey that included questions about demographics, self-reported diagnoses and hemoglobin A1c (HbA1c), current IDS used, insulin therapy attitudes, current IDS features, and satisfaction with IDS. Univariate analyses identified variables associated with IDS satisfaction (P < 0.05); those variables were entered into stepwise linear regression analyses with IDS satisfaction as the dependent variable.

RESULTS

Six hundred sixty-seven individuals with type 2 diabetes participated (mean age, 57 years; 52% female; 88% Caucasian; 73% vial/syringe users, 27% insulin pen users). IDS satisfaction was associated (P < 0.05) with gender, health status, HbA1c, self-reported comorbidity, insulin therapy attitudes, IDS type, and evaluation of IDS features. Among individuals who reported their HbA1c (n = 438), the best predictors of IDS satisfaction were perceived effectiveness and value of insulin therapy, evaluation of IDS activity interference, and commitment to insulin therapy (R2 = 0.49, P < 0.001). Among all participants (n = 667), a second regression analysis that employed a variable representing report of HbA1c found the best predictors of IDS satisfaction included those in the first analysis with the addition of gender, report of HbA1c, and evaluation of IDS ease of use. These variables provided additional variance (R2 = 0.56, P < 0.001).

CONCLUSIONS

In people with type 2 diabetes, positive perceptions and attitudes about insulin therapy have greater influence than the type of IDS used on IDS satisfaction.

Transition probabilities and predictors of adherence in a California Medicaid population using antihypertensive and lipid-lowering medications

OBJECTIVES

To determine adherence rates, transition probabilities, and factors associated with transition from higher to lower adherence in antihypertensive (AH) and lipid-lowering (LL) medications.

METHODS

California Medicaid data (1995-2003) were used to identify hypertensive patients with prescriptions for both AH and LL medications. Proportion of days covered (PDC) was used to define three adherence classifications: fully adherent (FA, PDC >or= 0.8), partially adherent (PA, 0.2 <or= PDC < 0.8), and nonadherent (NA, PDC < 0.2). Annual transition matrices documented the probability of adherence status changes.

RESULTS

Only 13% of the 5943 patients were FA to both drugs at baseline. Patients who were FA (60%) or NA (84%) to both drugs had high probability of maintaining status at year two (Y2). Significant variables associated with a transition from adherent to NA at Y2 included African American race (odds ratio [OR] 1.5), other race groups (OR 1.2), lack of Medicare eligibility (OR 1.3), and initiating LL therapy of fibric acid derivatives (OR 1.3) or niacin (OR 1.8).

CONCLUSIONS

Patients FA or NA with both drugs at baseline were more likely to maintain their adherence status. Race, insurance coverage, and type of LL medication were significantly associated with transitioning from any adherence status to nonadherence. These findings may be useful in guiding cost-effectiveness analyses incorporating adherence estimates.

Factors associated with first-fill adherence rates for diabetic medications: a cohort study

BACKGROUND

Little is known about first-fill adherence rates for diabetic medications and factors associated with non-fill.

OBJECTIVE

To assess the proportion of patients who fill their initial prescription for a diabetes medication, understand characteristics associated with prescription first-fill rates, and examine the effect of first-fill rates on subsequent A1c levels.

DESIGN

Retrospective, cohort study linking electronic health records and pharmacy claims.

PARTICIPANTS

One thousand one hundred thirty-two patients over the age of 18 who sought care from the Geisinger Clinic, had Geisinger Health Plan pharmacy benefits, and were prescribed a diabetes medication for the first time between 2002 and 2006.

MEASUREMENTS

The primary outcome of interest was naïve prescription filled by the patient within 30 days of the prescription order date.

RESULTS

The overall first-fill adherence rate for antidiabetic drugs was 85%. Copays < $10 (OR 2.22, 95% CI 1.57-3.14) and baseline A1c > 9% (OR 2.63, 95% CI 1.35, 5.09) were associated with improved first-fill rates while sex, age, and co-morbidity score had no association. A1c levels decreased among both filling and non-filling patients though significantly greater reductions were observed among filling patients. Biguanides and sulfonylureas had higher first-fill rates than second-line oral agents or insulin.

CONCLUSIONS

First-fill rates for diabetes medication have room for improvement. Several factors that predict non-filling are readily identifiable and should be considered as possible targets for interventions.

Clinical and behavioral correlates of achieving and maintaining glycemic targets in an underserved population with type 2 diabetes

OBJECTIVE

In an underserved Latino area, we established a disease-management program and proved its effectiveness. However, many patients still remained above target. This study was designed to evaluate which factors are associated with reaching program goals.

RESEARCH DESIGN AND METHODS

This was a randomized, prospective, observational study in which patients enrolled in our program were followed for 2 years with outcomes, measures, and questionnaires assessed at baseline and at 6, 12, and 24 months.

RESULTS

Overall, A1C fell by 1%. Adherence to medication was the strongest predictor of reaching the target A1C of <8%; baseline A1C was also predictive. Knowledge scores increased in those who reached target, but the measures of self-efficacy and empowerment did not change for either group.

CONCLUSIONS

Diabetes management is effective in a lower-income Latino population. However, adherence was suboptimal even when medications were provided on-site for free. Further research into barriers associated with medication adherence is needed.

A novel method for measuring patients' adherence to insulin dosing guidelines: introducing indicators of adherence

Background

Diabetic type 1 patients are often advised to use dose adjustment guidelines to calculate their doses of insulin. Conventional methods of measuring patients' adherence are not applicable to these cases, because insulin doses are not determined in advance. We propose a method and a number of indicators to measure patients' conformance to these insulin dosing guidelines.

Methods

We used a database of logbooks of type 1 diabetic patients who participated in a summer camp. Patients used a guideline to calculate the doses of insulin lispro and glargine four times a day, and registered their injected doses in the database. We implemented the guideline in a computer system to calculate recommended doses. We then compared injected and recommended doses by using five indicators that we designed for this purpose: absolute agreement (AA): the two doses are the same; relative agreement (RA): there is a slight difference between them; extreme disagreement (ED): the administered and recommended doses are merely opposite; Under-treatment (UT) and over-treatment (OT): the injected dose is not enough or too high, respectively. We used weighted linear regression model to study the evolution of these indicators over time.

Results

We analyzed 1656 insulin doses injected by 28 patients during a three weeks camp. Overall indicator rates were AA = 45%, RA = 30%, ED = 2%, UT = 26% and OT = 30%. The highest rate of absolute agreement is obtained for insulin glargine (AA = 70%). One patient with alarming behavior (AA = 29%, RA = 24% and ED = 8%) was detected. The monitoring of these indicators over time revealed a crescendo curve of adherence rate which fitted well in a weighted linear model (slope = 0.85, significance = 0.002). This shows an improvement in the quality of therapeutic decision-making of patients during the camp.

Conclusion

Our method allowed the measurement of patients' adherence to their insulin adjustment guidelines. The indicators that we introduced were capable of providing quantitative data on the quality of patients' decision-making for the studied population as a whole, for each individual patient, for all injections, and for each time of injection separately. They can be implemented in monitoring systems to detect non-adherent patients.

The effects of health plan copayments on adherence to oral diabetes medication and health resource utilization

OBJECTIVE

To assess the effects of copayments on oral diabetes medication adherence, health resource utilization, and expenditure.

METHODS

Retrospective, observational analysis of medical and pharmacy claims data from PPG Industries employees, retirees, and dependents (2003-2005). Average monthly copayments were stratified low (US$0-9), medium (US$10-19), or high (US$20+).

RESULTS

In 2052 individuals, adherence to oral diabetes medication was highest for the low copayment group for both age groups >or=65 years; 84% low, 77% medium, 64% high (P < 0.0001) and <65 years; 74% low, 71% medium, 55% high (P < 0.0001). For patients <65 years, total health care expenditure was 22% lower in the low versus high copayment group (P = 0.024), resulting in average savings of US $3116 per patient per year. Risk of hospitalization was significantly lower in the low versus the high copayment group for patients >or=65 years of age.

CONCLUSIONS

High copayments were associated with lower adherence to oral diabetes medications for all patients and higher total health care costs for patients less than 65.

Identification of documented medication non-adherence in physician notes

Medication non-adherence is common and the physicians awareness of it may be an important factor in clinical decision making. Few sources of data on physician awareness of medication non-adherence are available. We have designed an algorithm to identify documentation of medication non-adherence in the text of physician notes. The algorithm recognizes eight semantic classes of documentation of medication non-adherence. We evaluated the algorithm against manual ratings of 200 randomly selected notes of hypertensive patients. The algorithm detected 89% of the notes with documented medication non-adherence with specificity of 84.7% and positive predictive value of 80.2%. In a larger dataset of 1,000 documents, notes that documented medication non-adherence were more likely to report significantly elevated systolic (15.3% vs. 9.0%; p = 0.002) and diastolic (4.1% vs. 1.9%; p = 0.03) blood pressure. This novel clinically validated tool expands the range of information on medication non-adherence available to researchers.

A qualitative exploration of multiple medicines beliefs in co-morbid diabetes and cardiovascular disease

AIM

Multiple medicines are typically prescribed for patients with Type 2 diabetes (T2D) and cardiovascular disease (CVD). Non-adherence to medicines can arise for those who self-manage the complex regimens typical of T2D and CVD. Perceptions about treatment and illness are probable drivers of adherence and self-management behaviours. However, few studies have explored perceptions about multiple medicines and none has examined the complexities of managing medicines used in T2D and CVD. We explored perceptions towards multiple medicines expressed by people managing co-morbid T2D and CVD.

METHOD

Nineteen adults managing multiple medicines for T2D and CVD participated in semi-structured interviews. The interviews were analysed using a modified grounded theory framework.

RESULTS

Participants were sceptical about the prescription of additional medicines, particularly CVD medicines. Often medicines for T2D management were thought to be more important than medicines prescribed for CVD management. Lifestyle change was thought to be a way of reducing CVD risk and this was related to the lower status given to CVD medication. Lipid-lowering medicines were often thought to be the least important CVD medication prescribed, with some participants considering cessation of medicines to test their necessity.

CONCLUSIONS

Despite evidence on the severity of macrovascular complications in T2D being available, participants in this study undervalued their CVD medications. Survey research is needed to assess how widely held these beliefs are and whether these beliefs influence non-adherence. Future research should explore how healthcare professionals can best address such beliefs.

Impact of disease management on utilization and adherence with drugs and tests: the case of diabetes treatment in the Florida: a Healthy State (FAHS) program

OBJECTIVE

The purpose of this study was to evaluate the effect of telephonic care management within a diabetes disease management program on adherence to treatment with hypoglycemic agents, ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), statins, and recommended laboratory tests in a Medicaid population.

RESEARCH DESIGN AND METHODS

A total of 2,598 patients with diabetes enrolled for at least 2 years in Florida: A Healthy State (FAHS), a large Medicaid disease management program, who received individualized telephonic care management were selected if they were eligible for at least 12 months before and 12 months after beginning care management. Patients were matched one-to-one on all baseline characteristics to 2,598 control patients. The impact of care management on utilization and adherence rates for diabetes-related medications and tests was analyzed with the difference-in-difference estimator.

RESULTS

Changes in utilization were evaluated separately for those who were characterized as adherent to treatment at baseline ("users") and those who were not ("nonusers"). Both groups achieved significant improvement in adherence between baseline and follow-up. Nonusers increased their overall hypoglycemic use by 0.7 script (P < 0.001), by 0.7 script for ACEIs and statins (both P < 0.001), by 0.8 test for A1C (P < 0.001), and by 0.7 test for lipids (P < 0.001). Users increased hypoglycemic use by 1.5 scripts (P < 0.001) and insulin use by 0.9 script (P < 0.001).

CONCLUSIONS

The FAHS telephonic care management intervention effectively induced Medicaid patients with diabetes to begin treatment and improved adherence to oral hypoglycemic agents and recommended tests. It also substantially improved adherence among baseline insulin users.

Effect of non-persistent use of oral glucose-lowering drugs on HbA1c goal attainment

OBJECTIVES

The aim of this study was to quantify the effect of non-persistence with oral glucose-lowering drugs (OGLD) on HbA(1c) goal attainment (<7%) in daily practice.

METHODS

From the PHARMO Record Linkage System comprising among others linked drug dispensing and clinical laboratory data from approximately 2.5 million individuals in the Netherlands, new users of OGLD in the period 1999-2004 were identified. Patients with a baseline HbA(1c) > or =7% and at least one HbA(1c) measurement in the period of 6-12 months after treatment onset were included in the study cohort. Persistence with OGLD in the first year of treatment was determined using the method of Catalan. In case the first treatment episode overlapped the first HbA(1c) measurement within 6-12 months after treatment onset, a patient was considered persistent at that measurement. Patients with a HbA(1c) <7% were defined as having attained goal.

RESULTS

The study cohort included 2023 patients with a mean baseline HbA(1c) of 8.9 +/- 1.8%. Three-quarters (1512 patients) were persistent with any OGLD at the first HbA(1c) measurement within 6-12 months after treatment onset; of these, 861 (57%) were at goal. Of the 511 non-persistent patients, 239 (47%) were at goal. Non-persistent patients were about 20% less likely to attain goal (RRadj 0.82; 95%CI 0.74-0.91), compared to persistent OGLD users.

CONCLUSION

Non-persistent use of OGLD leads to a 20% decreased probability of HbA(1c) goal attainment in daily practice. This effect of non-persistence seems modest, but represents around 12 000 new and 10 000 prevalent OGLD users a year in the Netherlands in whom OGLD use could be better controlled.

Self-care practices of Malaysian adults with diabetes and sub-optimal glycaemic control

OBJECTIVE

To investigate the self-care practices of Malaysian adults with diabetes and sub-optimal glycaemic control.

METHODS

Using a one-to-one interviewing approach, data were collected from 126 diabetic adults from four settings. A 75-item questionnaire was used to assess diabetes-related knowledge and self-care practices regarding, diet, medication, physical activity and self-monitoring of blood glucose (SMBG).

RESULTS

Most subjects had received advice on the importance of self-care in the management of their diabetes and recognised its importance. Sixty-seven subjects (53%) scored below 50% in their diabetes-related knowledge. Subjects who consumed more meals per day (80%), or who did not include their regular sweetened food intakes in their daily meal plan (80%), or who were inactive in daily life (54%), had higher mean fasting blood glucose levels (p=0.04). Subjects with medication non-adherence (46%) also tended to have higher fasting blood glucose levels. Only 15% of the subjects practiced SMBG. Predictors of knowledge deficit and poor self-care were low level of education (p = <0.01), older subjects (p=0.04) and Type 2 diabetes subjects on oral anti-hyperglycaemic medication (p = <0.01).

CONCLUSION

There were diabetes-related knowledge deficits and inadequate self-care practices among the majority of diabetic patients with sub-optimal glycaemic control.

PRACTICE IMPLICATIONS

This study should contribute to the development of effective education strategies to promote health for adults with sub-optimal diabetes control.

Effects of increased patient cost sharing on socioeconomic disparities in health care

BACKGROUND

Increasing patient cost sharing is a commonly employed mechanism to contain health care expenditures.

OBJECTIVE

To explore whether the impact of increases in prescription drug copayments differs between high- and low-income areas.

DESIGN

Using a database of 6 million enrollees with employer-sponsored health insurance, econometric models were used to examine the relationship between changes in drug copayments and adherence with medications for the treatment of diabetes mellitus (DM) and congestive heart failure (CHF).

SUBJECTS

Individuals 18 years of age and older meeting prespecified diagnostic criteria for DM or CHF were included.

MEASUREMENTS

Median household income in the patient's ZIP code of residence from the 2000 Census was used as the measure of income. Adherence was measured by medication possession ratio: the proportion of days on which a patient had a medication available.

RESULTS

Patients in low-income areas were more sensitive to copayment changes than patients in high- or middle-income areas. The relationship between income and price sensitivity was particularly strong for CHF patients. Above the lowest income category, price responsiveness to copayment rates was not consistently related to income.

CONCLUSIONS

The relationship between medication adherence and income may account for a portion of the observed disparities in health across socioeconomic groups. Rising copayments may worsen disparities and adversely affect health, particularly among patients living in low-income areas.

Development of the ASK-20 adherence barrier survey

OBJECTIVE

Poor medication adherence is widespread among patients with chronic conditions requiring long-term drug therapy. Medication adherence is determined by multiple patient-, context-, and therapy-dependent factors. This paper describes the development and initial validation of the ASK-20 survey, created to identify actionable risk factors for medication nonadherence and to improve communication about adherence.

METHODS

A pool of 30 items was generated through comprehensive literature review. Items were refined and the item pool was expanded through an expert panel review and patient focus groups to yield 47 candidate items, each with five response options ranging from either Strongly Agree to Strongly Disagree or from In the Last Week to Never. The pool of 47 candidate items was administered to a web-based sample of 605 patients taking medications and reporting a diagnosis of asthma, diabetes, or depression for psychometric testing and item reduction.

RESULTS

Eleven multi-item factor groupings with two additional unique items were identified on the basis of principal components analysis and interpretability. Twenty (20) items representing ten factor groupings were selected for the final instrument. Each of the final items was dichotomized as positive - indicating a barrier, or negative. Two summary scores - the sum of all positive barriers or Total Barrier Count (TBC) and the sum of raw item scores, the ASK-20 score - were calculated. Concurrent validity of the dichotomously scored individual items, the TBC and ASK-20 scores in relation to self-reported adherence was generally good. Cronbach's alpha coefficient was 0.77 for the TBC and 0.85 for the ASK-20 score.

CONCLUSIONS

ASK-20 consists of 20 clinically actionable items representing multiple factors that affect medication adherence. The ASK-20 survey demonstrated satisfactory validity and internal consistency and may be used to identify actionable barriers to adherence across a spectrum of chronic diseases. Future research using more objective measures of adherence is warranted to confirm the exploratory validity and reliability of ASK-20 reported in this study.

Hypoglycaemic symptoms, treatment satisfaction, adherence and their associations with glycaemic goal in patients with type 2 diabetes mellitus: findings from the Real-Life Effectiveness and Care Patterns of Diabetes Management (RECAP-DM) Study

AIMS

This study was undertaken to evaluate (i) factors associated with patient-reported hypoglycaemia; (ii) association of patient-reported hypoglycaemic symptoms with treatment satisfaction and barriers to adherence and (iii) association between treatment satisfaction, adherence and glycaemic control among patients with type 2 diabetes who added a sulphonylurea or a thiazolidinedione to ongoing metformin.

METHODS

This observational, cross-sectional, multicentre study was conducted in seven countries (Finland, France, Germany, Norway, Poland, Spain and UK) from June 2006 to February 2007. Patients with type 2 diabetes who added a sulphonylurea or a thiazolidinedione to ongoing metformin therapy on a date (index date) from January 2001 through January 2006 and who had at least one haemoglobin A1C (HbA1C) measurement in the 12-month period before the visit date were eligible. Questionnaires were used to ascertain patients' reports of hypoglycaemic symptoms, treatment satisfaction, and treatment adherence. The Treatment Satisfaction Questionnaire for Medication was used to measure patients' treatment satisfaction. An adherence and barriers questionnaire was used to measure patients' adherence to treatment. Glycaemic control was based on documented HbA1C measurements within the prior 12 months.

RESULTS

The mean +/- s.d. age was 62.9 +/- 10.6 years, and the mean +/- s.d. duration of diabetes was 7.8 +/- 5.1 years. HbA1C in this population of patients who had failed metformin monotherapy and were treated with oral antihyperglycaemic agents was below the International Diabetes Federation goal of 6.5% in only 477 (27.9%) patients. Approximately 38% of patients reported hypoglycaemic symptoms during the past year. Hypoglycaemia was significantly more likely in patients with a history of macrovascular complications of diabetes (OR = 1.346; 95% CI = 1.050-1.725) and with no regular physical activity (OR = 1.295; 95% CI = 1.037-1.618). Patients reporting hypoglycaemia had significantly lower treatment satisfaction scores (71.6 +/- 17.6 vs. 76.3 +/- 16.8; p < 0.0001 for global satisfaction). Compared with their counterparts reporting no hypoglycaemic symptoms, patients with such symptoms were also significantly more likely to report barriers to adherence, including being unsure about instructions (37.0 vs. 30.5%; p = 0.0057). Patients at HbA1C goal had significantly higher treatment satisfaction and adherence compared with those who were not.

CONCLUSIONS

Patients' reports of hypoglycaemic symptoms are common in European outpatients with type 2 diabetes and are associated with significantly lower treatment satisfaction and with barriers to adherence. In addition, being at HbA1C goal is associated with treatment satisfaction and adherence.

Medication adherence and racial differences in A1C control

OBJECTIVE

The purpose of this study was to examine medication adherence and other self-management practices as potential determinants of higher glycemic risk among black relative to white patients.

RESEARCH DESIGN AND METHODS

We used a retrospective, longitudinal repeated-measures design to model the contribution of medication adherence to black-white differences in A1C among type 2 diabetic patients at a large multispecialty group practice. We identified 1,806 adult (aged >/=18 at diagnosis) patients (467 black and 1,339 white) with newly initiated oral hypoglycemic therapy between 1 December 1994 and 31 December 2000. Race was identified using an electronic medical record and patient self-report. Baseline was defined as the 13 months preceding and included the month of therapy initiation. All patients were required to have at least 12 months of follow-up.

RESULTS

At initiation of therapy, black patients had higher average A1C values compared with whites (9.8 vs. 8.9, a difference of 0.88; P < 0.0001). Blacks had lower average medication adherence during the first year of therapy (72 vs. 78%; P < 0.0001). Although more frequent medication refills were associated with lower average A1C values, adjustment for adherence did not eliminate the black-white gap.

CONCLUSIONS

We found persistent racial differences in A1C that were not explained by differences in medication adherence. Our findings suggest that targeting medication adherence alone is unlikely to reduce disparities in glycemic control in this setting. Further research is needed to explore possible genetic and environmental determinants of higher A1C among blacks at diagnosis, which may represent a critical period for more intensive intervention.

Why don't diabetes patients achieve recommended risk factor targets? Poor adherence versus lack of treatment intensification

BACKGROUND

Despite the availability of effective hypertension, hyperlipidemia, and hyperglycemia therapies, target levels of systolic blood pressure (SBP), LDL-cholesterol (LDL-c), and hemoglobin A1c control are often not achieved.

OBJECTIVE

To examine the relative importance of patient medication nonadherence versus clinician lack of therapy intensification in explaining above target cardiovascular disease (CVD) risk factor levels.

DESIGN

Cross-sectional assessment.

PARTICIPANTS

In 2005, 161,697 Kaiser Permanente Northern California adult diabetes patients were included in the study.

MEASUREMENT

"Above target" was defined as most recent A1c >/=7.0% for hyperglycemia, LDL-c >/=100 mg/dL for hyperlipidemia, and SBP >/=130 mmHg for hypertension. Poor adherence was defined as medication gaps for >/=20% of days covered for all medications for each condition separately. Treatment intensification was defined as an increase in the number of drug classes, increased dosage of a class, or a switch to a different class within the 3 months before or after notation of above target levels.

RESULTS

Poor adherence was found in 20-23% of patients across the 3 conditions. No evidence of poor adherence with no treatment intensification was found in 30% of hyperglycemia patients, 47% of hyperlipidemia patients, and 36% of hypertension patients. Poor adherence or lack of therapy intensification was evident in 53-68% of patients above target levels across conditions.

CONCLUSIONS

Both nonadherence and lack of treatment intensification occur frequently in patients above target for CVD risk factor levels; however, lack of therapy intensification was somewhat more common. Quality improvement efforts should focus on these modifiable barriers to CVD risk factor control.

Educational interventions aiming at improving adherence to treatment recommendations in type 2 diabetes: A sub-analysis of a systematic review of randomised controlled trials

OBJECTIVE

In the management of type 2 diabetes, a complex interaction takes place between medical professionals' treatment goals and patients' health beliefs about the disease and its treatment options. The contribution of self-management education to adherence in general or even more specifically to medicine taking is not known. We assessed educational interventions aimed at improving adherence to medical treatment recommendations, other than lifestyle advice.

STUDY DESIGN

Systematic literature review.

SETTING

This paper represents an analysis of eight articles describing an educational intervention as a subgroup of a Cochrane Review [E. Vermeire, J. Wens, P. Van Royen, Y. Biot, H. Hearnshaw, A. Lindenmeyer, Interventions for improving adherence to treatment recommendations in people with type 2 diabetes mellitus, Cochrane Database of Systematic Reviews 2005, Issue 2, Art. No.: CD003638, doi:10.1002/14651858.CD003638.pub2] on interventions to improve adherence to treatment recommendations in people with type 2 diabetes.

RESULTS

Four studies reported interventions using face-to-face education, two reported on the effects of group education and two on distance education by telemedicine. Due to poor quality of study designs, a variety of heterogeneous outcome measures in different time intervals, unclear definitions of adherence, and difficulties in evaluating different aspects of education performed, general conclusions could not be drawn.

CONCLUSION

Consistent conclusions about the effectiveness of educational interventions on adherence to treatment recommendations were hard to be drawn. There is an urgent need for well-designed intervention studies on the effect of different aspects of education on adherence to treatment recommendations.

Treatment of type 2 diabetes with combined therapy: what are the pros and cons?

Type 2 diabetes is a progressive syndrome that evolves toward complete insulin deficiency during the patient's life. A stepwise approach for its treatment should be tailored according to the natural course of the disease, including adding insulin when hypoglycemic oral agent failure occurs. Treatment with insulin alone should eventually be considered in a relevant number of cases. Experience has shown the protective effects of insulin on beta-cell survival and function, resulting in more stable metabolic control. On the contrary, treatment with most insulin secretagogues has been associated with increased beta-cell apoptosis, reduced responsiveness to high glucose, and impairment of myocardial function during ischemic conditions. In addition, macrovascular complications are associated with postprandial hyperglycemia, indicating the need for tight glycemic control. Insulin treatment, especially with rapid-acting analogs, has been demonstrated to successfully control postprandial glucose excursions. Finally, a reason for concern with regard to combined therapy is represented by the evidence that polipharmacy reduces compliance to the treatment regimen. This can be particularly relevant in patients with type 2 diabetes usually taking drugs for complications and for concomitant diseases with consequent deterioration not only of metabolic control but also of other conditions. In conclusion, therapy with insulin alone immediately after hypoglycemic oral agent failure may be a useful and safe therapeutic approach in type 2 diabetes.

Race/ethnicity and economic differences in cost-related medication underuse among insured adults with diabetes: the Translating Research Into Action for Diabetes Study

OBJECTIVE

To examine racial/ethnic and economic variation in cost-related medication underuse among insured adults with diabetes.

RESEARCH DESIGN AND METHODS

We surveyed 5,086 participants from the multicenter Translating Research Into Action for Diabetes Study. Respondents reported whether they used less medication because of cost in the past 12 months. We examined unadjusted and adjusted rates of cost-related medication underuse, using hierarchical regression, to determine whether race/ethnicity differences still existed after accounting for economic, health, and other demographic variables.

RESULTS

Participants were 48% white, 14% African American, 14% Latino, 15% Asian/Pacific Islander, and 8% other. Overall, 14% reported cost-related medication underuse. Unadjusted rates were highest for Latinos (23%) and African Americans (17%) compared with whites (13%), Asian/Pacific Islanders (11%), and others (15%). In multivariate analyses, race/ethnicity significantly predicted cost-related medication underuse (P = 0.048). However, adjusted rates were only slightly higher for Latinos (14%) than whites (10%) (P = 0.026) and were not significantly different for African Americans (11%), Asian/Pacific Islanders (7%), and others (11%). Income and out-of-pocket drug costs showed the greatest differences in adjusted rates of cost-related medication underuse (15 vs. 5% for participants with income <or=$25,000 vs. >$50,000 and 24 vs. 7% for participants with out-of-pocket costs >$150 per month vs. <or=$50 per month.

CONCLUSIONS

One in seven participants reported cost-related medication underuse. Rates were highest among African Americans and Latinos but were related to lower incomes and higher out-of-pocket drug costs in these groups. Interventions to decrease racial/ethnic disparities in cost-related medication underuse should focus on decreasing financial barriers to medications.

Medication taking and diabetes: a systematic review of the literature

PURPOSE

The purpose of this systematic review is to evaluate the evidence of the challenges and barriers to medication taking (adherence) and to summarize the interventions that improve medication taking in type 1 and type 2 diabetes mellitus.

METHODS

PubMed, the Cochrane Collaborative, and the Health and Psychosocial Instruments databases were used to obtain articles identified by using the MeSH headings of diabetes, medication, oral hypoglycemic agents, oral antihyperglycemic agents, oral antidiabetic agents, insulin, adherence, medication taking, compliance, fears, treatment, and electronic monitoring. Only articles published in English between 1990 and May 7, 2007, and including individuals of all ages with type 1 or type 2 diabetes mellitus were included. Retrospective and prospective studies reporting adherence to medications using self-report, pill counts, medication possession ratios, and electronic monitoring devices were included. Database analyses of prescription records from various organizations or countries were included only if adherence to pharmacologic therapy was stated. Surveys and questionnaires assessing medication taking were also included. The data from the selected literature was abstracted independently. The various studies were grouped together based on the type of study conducted. Studies were not included if a specific measure of adherence to medication was not used or stated. The studies are presented in 3 tables according to design.

CONCLUSIONS

Several barriers to medication taking have been suggested for those with diabetes mellitus, although well-controlled trials to confirm and resolve these barriers are limited. Diabetes educators should be aware of the common barriers to medication taking (regimen complexity of more than 1 diabetes mellitus drug or more than 1 dose daily, depression, and remembering doses and refills) and provide screening and support to their patients to resolve barriers if they exist. Further studies are needed to test specific interventions to improve medication taking in diabetes.

The significance of compliance and persistence in the treatment of diabetes, hypertension and dyslipidaemia: a review

OBJECTIVES

To review studies of patient compliance/persistence with cardiovascular or antidiabetic medication published since the year 2000; to compare the methods used to measure compliance/persistence across studies; to compare reported compliance/persistence rates across therapeutic classes and to assess whether compliance/persistence correlates with clinical outcomes.

METHODS

English language papers published between January 2000 and November 2005 investigating patient compliance/persistence with cardiovascular or antidiabetic medication were identified through searches of the MEDLINE and EMBASE databases. Definitions and measurements of compliance/persistence were compared across therapeutic areas using contingency tables.

RESULTS

Of the 139 studies analysed, 32% focused on hypertension, 27% on diabetes and 13% on dyslipidaemia. The remainder covered coronary heart disease and cardiovascular disease (CVD) in general. The most frequently reported measure of compliance was the 12-month medication possession ratio (MPR). The overall mean MPR was 72%, and the MPR did not differ significantly between treatment classes (range: 67-76%). The average proportion of patients with an MPR of >80% was 59% overall, 64% for antihypertensives, 58% for oral antidiabetics, 51% for lipid-lowering agents and 69% in studies of multiple treatments, again with no significant difference between treatment classes. The average 12-month persistence rate was 63% and was similar across therapeutic classes. Good compliance had a positive effect on outcome in 73% of the studies examining clinical outcomes.

CONCLUSIONS

Non-compliance with cardiovascular and antidiabetic medication is a significant problem, with around 30% of days 'on therapy' not covered by medication and only 59% of patients taking medication for more than 80% of their days 'on therapy' in a year. Good compliance has a positive effect on clinical outcome, suggesting that the management of CVD may be improved by improving patient compliance.

Combination treatment in the management of type 2 diabetes: focus on vildagliptin and metformin as a single tablet

Vildagliptin is a potent and selective inhibitor of dipeptidyl peptidase-IV (DPP-4), orally active, that improves glycemic control in patients with type 2 diabetes (T2DM) primarily by enhancing pancreatic (alpha and beta) islet function. Thus vildagliptin has been shown both to improve insulin secretion and to suppress the inappropriate glucagon secretion seen in patients with T2DM. Vildagliptin reduces HbA(1c) when given as monotherapy, without weight gain and with minimal hypoglycemia, or in combination with the most commonly prescribed classes of oral hypoglycemic drugs: metformin, a sulfonylurea, a thiazolidinedione, or insulin. Metformin, with a different mode of action not addressing beta-cell dysfunction, has been used for about 50 years and still represents the universal first line therapy of all guidelines. However, given the multiple pathophysiological abnormalities in T2DM and the progressive nature of the disease, intensification of therapy with combinations is typically required over time. Recent guidelines imply that patients will require pharmacologic combinations much earlier to attain and sustain the increasingly stringent glycemic targets, with careful drug selection to avoid unwanted adverse events, especially hypoglycemia. The combination of metformin and vildagliptin offers advantages when compared to currently used combinations with additive efficacy and complimentary mechanisms of action, since it does not increase the risk of hypoglycemia and does not promote weight gain. Therefore, by specifically combining these agents in a single tablet, there is considerable potential to achieve better blood glucose control and to improve compliance to therapy.

The effect of advanced access implementation on quality of diabetes care

INTRODUCTION

The study analyzes the effect of an advanced access program on quality of diabetes care.

METHODS

We conducted this study in a medical group of 240,000 members served by 17 primary care clinics. Seven thousand adult patients older than 18 years of age with diabetes were identified from administrative databases. Two aspects of advanced access - wait time for appointments and continuity of care - were calculated yearly for each patient during 1999 through 2001. We developed three composite measures of glucose and lipid control - process (proportion of patients with appropriate testing rates of hemoglobin A1c [HbA1c] and low-density lipoprotein [LDL]), good control (proportion with HbA1c < 8% and LDL < 130 mg/dL) and excellent control (proportion with HbA1c < 7% and LDL < 100 mg/dL) - and assessed them each year for each patient. We used multilevel logistic regression to predict the measures in 2000 and 2001 (years during and after advanced access implementation) relative to 1999 (year pre-advanced access).

RESULTS

After implementation of advanced access, wait time decreased from 21.6 days to 4.2 days, and continuity improved by 6.5% (both P < .01). The percentage of patients with HbA1c < 7% increased from 44.4% to 52.3% and with LDL < 100 mg/dL from 29.8% to 38.7%. Increased continuity predicted improved process (P = .01), good control (P = .033), and excellent control (P < .001). However, wait time did not significantly predict process (P = .62) or quality measures (P = .95).

CONCLUSION

Measures of the quality of diabetes control improved in the year after implementation of advanced access, but better care did not correlate with decreased wait time to see a provider. However, improved continuity of care predicted improvements in both process and quality of diabetes care.

Patients with asthma who do not fill their inhaled corticosteroids: a study of primary nonadherence

BACKGROUND

Adherence to inhaled corticosteroids (ICSs) is known to be poor among patients with asthma; however, little is known about patients who do not fill their ICS prescriptions (ie, primary nonadherence).

OBJECTIVE

To estimate rates of primary nonadherence and to explore associated factors.

METHODS

The study population was members of a large health maintenance organization in southeast Michigan who met the following criteria: age 5 to 56 years; previous diagnosis of asthma; at least 1 electronic prescription for an ICS between February 17, 2005, and June 1, 2006; and at least 3 months follow-up after the ICS prescription. Adherence was estimated by using electronic prescription information and pharmacy claims data. Multivariable stepwise analysis was used to identify factors associated with primary nonadherence compared with adherent patients.

RESULTS

One thousand sixty-four patients met the study criteria and had calculable adherence. Of these patients, 82 (8%) never filled their ICS prescription. Stepwise regression identified the following factors to be associated with an increased likelihood of primary nonadherence: younger age, female sex, African American race-ethnicity, and lower rescue medication use. Factors associated with primary nonadherence differed between race-ethnic groups.

CONCLUSION

Primary nonadherence was associated with lower baseline rescue medication use, which may reflect lower perceived need for ICS therapy in patients with milder asthma. Rates of primary nonadherence and the factors which influenced this outcome differed by race-ethnicity.

CLINICAL IMPLICATIONS

Understanding patient characteristics associated with primary nonadherence may be important for disease management, because many patients with asthma do not fill their ICS prescriptions.

Treatment adherence among primary care patients in a historically disadvantaged community in South Africa: a qualitative study

The present study examined the issue of treatment adherence among a sample of 23 rural South African patients living with either hypertension or diabetes, or both. The sample was asked to participate in qualitative interviews that asked about various aspects of their experience of their illness and treatment. The analysis of the data focused on the content of participants' concerns and difficulties with adhering to treatment recommendations. The themes that emerged from the study were participants' attribution of the origin of their illness, their subjective experience of their illness, their concerns about the consequences of poor adherence, financial problems and psychosocial support.

Hypertension treatment in a medicare population: Adherence and systolic blood pressure control

BACKGROUND

Despite substantial trial evidence that demonstrates the effectiveness of pharmacologic treatment for reducing blood pressure (BP) and cardiovascular events, many patients are nonadherent to their hypertension treatment.

OBJECTIVES

The purpose of this study was to examine patient adherence to hypertension medications using pharmacy data (ie, outpatient, inpatient, and mail-order prescriptions) and the association between adherence measures and systolic BP (SBP) control.

METHODS

The study included Medicare + Choice beneficiaries (aged > or = 65 years) who were continuously enrolled in an integrated delivery system in 2003, and who had documented hypertension and received > or = 1 hypertension drug in 2002. This analysis used automated clinical data and the 2000 US Census. We estimated 2 measures of hypertension treatment adherence in 2003 using the supply of dispensed drugs in days (proportion of days covered > or = 80%): (1) adherence to > or = 1 hypertension drug; and (2) adherence to the full hypertension treatment regimen. We defined the regimen by the number of hypertension drugs used concurrently in 2002. We assessed adherence annually and during the 30, 60, and 90 days before an SBP measurement. Logistic regression was used to examine the association between adherence and the number of drugs in the hypertension regimen, as well as the association between adherence and elevated SBP ( > or = 140 mm Hg). We adjusted for patient sociodemographic and clinical characteristics.

RESULTS

The majority (52.8%) of patients had multidrug hypertension regimens. In 2003, 87.3% of subjects were adherent to > or = 1 hypertension drug; 72.1% were adherent to their full regimen. After adjustment, we found that subjects with multidrug regimens were significantly more likely to be adherent to > or = 1 drug and significantly less likely to be adherent to their full regimen, compared with patients on a 1-drug regimen. Over one-third of subjects had elevated SBP in 2003. Both adherence measures were associated with lower odds of having elevated SBP (eg, odds ratio = 0.87 [95% CI, 0.84-0.89] for adherence to the full regimen). For subjects with multidrug regimens, partial adherence and nonadherence to the regimen were associated with higher odds of having elevated SBP.

CONCLUSIONS

Adherence measures using automated pharmacy data can identify patients who are nonadherent to their drug treatment regimen and who are more likely to have inadequately controlled BP. Adherence measures that account for the number of drugs in a patients' drug regimen might help identify additional patients at risk for poor BP outcomes due to partial treatment adherence.

How adherent to treatment with azathioprine are patients with Crohn's disease in long-term remission?

BACKGROUND

Patients with longstanding quiescent Crohn's disease on azathioprine usually maintain an excellent quality of life but are also concerned about long-term safety. This may affect adherence to treatment. The aim of the present study was to assess the adherence to azathioprine in a cohort of patients with Crohn's disease in long-term remission.

METHODS

Thirty patients with Crohn's disease in remission on azathioprine for > or =48 months were enrolled in the study. All were asked to record the number of azathioprine tablets they consumed daily. Notes were kept every other month for 6 months. Adherence was defined as consumption of > or =80% of medication.

RESULTS

Most patients (18/28, 74.3%) were not adherent to treatment. The mean (+/-SD) daily dose of azathioprine in adherent and nonadherent patients was 145 +/- 45 mg and 102 +/- 20 mg, respectively. However, there were no significant differences between the 2 groups in the mean IBDQ score and mean Crohn's Disease Activity Index (CDAI) score, both throughout the entire study and at each time point of the study. Male gender, single status, and consumption of >5 concomitant medications were associated with nonadherence.

CONCLUSIONS

Most patients with Crohn's disease in longstanding remission had low self-reported adherence to azathioprine. Both male gender and single status were associated with nonadherence to azathioprine, whereas disease factors were not related to self-reported adherence. Patients considered nonadherent to treatment maintained disease remission and a quality of life similar to patients who were adherent to treatment.

Evaluation of treatment adherence in type 1 diabetes: a novel approach

BACKGROUND

Intensified insulin therapy requires outstanding compliance but no measure of therapy adherence has been agreed upon. The aim of the current study was to test the hypothesis that treatment adherence, as described by a novel multiple regression model, relates to glycosylated haemoglobin and hypoglycaemia frequency in type 1 diabetes. Furthermore, we sought to analyse the complex diurnal patterns of therapy adherence.

MATERIALS AND METHODS

Thirty type 1 diabetes patients (20 females and 10 males), treated with intensified insulin therapy, were studied in a retrospective manner. Patients were trained to follow treatment algorithms for adjusting regular insulin dosage which took into account the actual blood glucose, food intake and the time of the day. By means of multiple linear regression analysis, with regular insulin dosage as the dependent variable, blood glucose and food intake as the independent variables, the insulin treatment algorithms actually used by the individual patient were retrieved. The correlation between prescribed and implemented insulin therapy served as a measure of adherence. Metabolic control was assessed by glycosylated haemoglobin and hypoglycaemia frequency.

RESULTS

Median glycosylated haemoglobin was 7.7% (range: 6.3-10.8); median monthly hypoglycaemia frequency was 3.8 (range: 0-9.8). Patients with good metabolic control (glycosylated haemoglobin < 7.7 and/or hypoglycaemia frequency < 3.8 per month) adhered to prescribed insulin dosing algorithms more frequently than those with poor metabolic control.

CONCLUSIONS

In patients with type 1 diabetes on intensified therapy a positive relationship between adherence to the therapy prescribed and metabolic control exists.

Indications for antidepressant drug prescribing in general practice in the Netherlands

BACKGROUND

The intensity of the use of antidepressants in large populations can nowadays relatively easily be estimated using databases encompassing prescription data. There are shortcomings when using prescription databases as they contain no clinical data on patient illness. Antidepressants are prescribed for different illnesses, thus information on the indications could help when interpreting results from database studies on antidepressant drug use. The aim of this study is to investigate for which indications antidepressants are being prescribed in general practice in the Netherlands.

METHODS

Data were obtained from the Second Dutch National Survey of General Practice, carried out by NIVEL (N=385,461). Patients, 18 years and older, who received an antidepressant prescription from a general practitioner in 2001 were selected (N=13,835). Indications for antidepressant drug prescribing were identified using time windows of different lengths.

RESULTS

Antidepressants are most often being prescribed for depression (45.5%) and anxiety/panic disorders (17.2%). For these indications lengthening the time window around prescription date from 0 to 180 days resulted in an increase of 20-40% in antidepressant drug users identified with these indications.

LIMITATION

None of our selected indications could be identified in the physician-patient contact file for about a third of the antidepressant drug users. The study was performed in a general practice setting and did not include antidepressant users who consult psychiatrists.

CONCLUSION

GPs prescribe antidepressants predominantly for treating depression. However, using antidepressant drug as a proxy for identifying depressed patients in a prescription database should be done with caution and when possible in combination with clinical data.

A connection between medication adherence, patient sense of uniqueness, and the personalization of information

Adherence to treatment regimens is important to achieve optimal disease management. However, nonadherence is evident across numerous clinical contexts, which leads to a higher disease burden on society. Among the various factors associated with patient adherence behavior, patient beliefs are the most influential set of factors. Several cognitive-social models and constructs that incorporate patient belief have been developed to explain patient health behaviors, such as the Health Belief Model, Self-Efficacy Model, Theory of Planned Behavior and so on. However, these models do not explain the formulation of health beliefs. The underlying mechanism accounting for patient variation in information processing that generates beliefs needs to be investigated, which will inform the development of interventions. We propose that patient's sense of uniqueness moderates the self-attribution of statistically-based information. Self-attribution is defined as a person's perceived probability that a statement applies to herself, and is influenced by experience and sense of uniqueness. Sense of uniqueness is a person's general belief regarding how unique she is. Statistically-based information is defined as information derived from or regarding aggregated effects or influences. Basically, the proposed hypothesis is that patients who have a stronger belief that they are unique are less likely to attribute to themselves statistically-based propositions regarding the majority of their group and are more likely to attribute to themselves statistically-based propositions regarding the minority. We further model the relationship between sense of uniqueness and self-attribution of information in terms of an idealized inexperienced person, and then extend the model to include the effect of personal experience. The estimation of hypothesis-specific effect parameters can be achieved by maximum likelihood. In conclusion, the sense of uniqueness hypothesis is general to the formulation of personal beliefs and consequently has implications for deliberate health behavior and indeed personal behavior in general.

A cross-national study of prescription nonadherence due to cost: data from the Joint Canada-United States Survey of Health

BACKGROUND

In Canada and the United States, patients who have difficulty paying for prescribed medications are less likely to obtain them and may experience increased risks for morbidity and mortality and/or increased health care costs due to nonadherence. As prescription drug costs have risen, the ability to pay for medications has emerged as a critical public health issue.

OBJECTIVES

The objectives of this study were to estimate the rates of cost-associated nonadherence in Canada and the United States, and to identify factors that predict cost-associated nonadherence in both countries.

METHODS

This original analysis used data from the 2002/2003 Joint Canada-US Survey of Health, a household phone survey jointly conducted by Statistics Canada (Ottawa, Ontario, Canada) and the US National Center for Health Statistics (Hyattsville, Maryland). The sample included 3505 adults in Canada and 5183 adults in the United States. Weighted group comparisons and logistic regression analyses were used to identify population factors predictive of cost-associated prescription nonadherence.

RESULTS

Residents of Canada were much less likely than residents of the United States to report cost-associated nonadherence (5.1% vs 9.9%; P < 0.001). Americans without health insurance (28.2%) and Americans and Canadians without prescription-drug coverage (16.2%) were significantly more likely than those with insurance (6.2%) to report cost-associated nonadherence (P < 0.001). In addition to country of residence and insurance coverage, significant risk factors predictive of nonadherence were young age, poor health, chronic pain, and low household income.

CONCLUSIONS

The results of this analysis suggest that people with low incomes and inadequate insurance, as well as those with poor health and/or chronic symptoms, are more likely to report failing to fill a prescription due to cost. The overall rate of cost-associated nonadherence was significantly higher in the United States than in Canada, even when other person-level factors were controlled for, including health insurance and prescription-drug coverage.

Therapeutic compliance: a prospective analysis of various factors involved in the adherence rate in type 2 diabetes

It's established that adherence rates to treatment are bad in chronic illnesses. The number of medicines prescribed and the rates of daily dosages have been shown to be of major influence for therapeutic compliance in AIDS or hypertension. Nevertheless, data on adherence to prescribed medications amongst diabetics are scarce. The aim of our study was to evaluate parameters influencing therapeutic compliance in type 2 diabetes. Adherence to treatment was evaluated by a questionnaire filled out during patient's hospitalisation in the diabetology department of a French general hospital of 450 beds. Factors influencing compliance were quantified taking into account demographic characteristics of our population, the treatments used, biological and medical data. 94 patients hospitalised for uncontrolled diabetes, aged 41-89 years, were studied. Non-adherence rate was high, 33 of them showed poor adherence to their drug treatment. Non-compliers were younger than compliant patients (56.5+/-12.1 vs. 65.5+/-12.5 years old; P<0.0001) and with a lower social position. Clinically, they were characterised by a shorter duration of diabetes and a lower number of clinical complications as macroangiopathy (6.9 vs. 33.3%; P=0.006). The number of daily doses or medicines didn't affect adherence rate. Improved control in therapeutic compliance may lead to better diabetic patients education. The implication is that instead of increasing the dose, changing the medication, or adding a second drug when glucose and HbA(1c)levels are high, clinicians should consider counselling patients on how to improve therapeutic compliance.

Effect of switching medically vulnerable patients with uncontrolled diabetes from isophane insulin human to insulin glargine

PURPOSE

The purpose of this observational study was to determine if switching from isophane insulin human (NPH) to insulin glargine would improve glycemic control in a medically vulnerable population with uncontrolled diabetes.

METHODS

A retrospective cohort review of patients' medical records was performed that recorded events occurring between January 1, 2001, and December 31, 2003. The cohort consisted of patients with diabetes in an adult medicine clinic at a county hospital. Patients were included if they were receiving NPH insulin for a minimum of six months and subsequently switched to insulin glargine for a minimum of six months.

RESULTS

The study included 43 patients. There was no significant difference in mean glycosylated hemoglobin (HbA(1c)) between NPH insulin (9.6%) and insulin glargine (9.7%) regimens (p = 0.78, 95% confidence interval, -0.62%, 0.82%). Neither was there a significant difference in the frequency or severity of hypoglycemic episodes between the two treatments. Patients experienced significantly fewer diabetes-associated visits over six months while on insulin glargine. Refill frequency did not differ significantly when patients were receiving NPH insulin versus insulin glargine. When analyzing patient characteristics, those of Hispanic ethnicity experienced HbA(1c) values significantly higher than white patients. Several characteristics were associated with refill frequency.

CONCLUSION

The results of our study indicate that both NPH- and glargine-based basal insulin regimens result in similar levels of glycemic control in a medically vulnerable population with diabetes, without significant differences in the number or severity of hypoglycemic episodes or in refill frequency.