Concordance between two methods in measuring treatment adherence in patients with type 2 diabetes

Flora López-Simarro,1 Carlos Brotons,2 Irene Moral,2 Alba Aguado-Jodar,3 Cèlia Cols-Sagarra,1 Sònia Miravet-Jiménez11Primary Health Care Center Martorell, Institut Català de la Salut, Barcelona, Spain; 2Research Unit, Sardenya Primary Health Care Center, Biomedical Research Institute Sant Pau (IIB Sant Pau), Teaching Unit of Family Medicine ACEBA, Barcelona, Spain; 3CAP Sagrada Família, Consorci Sanitari Integral, Barcelona, SpainObjective: We analyzed the concordance between two methods for measuring treatment adherence (TA) and studied the determinants of TA in patients with type 2 diabetes mellitus.Methods: We conducted a cross-sectional descriptive study in a primary care center, involving 320 diabetic patients. TA was measured using the Haynes–Sackett (H–S) adherence test during the patient interview and based on pharmacy refill data. TA was calculated globally and by drug groups (antihypertensive, lipid-lowering, and antidiabetic drugs).Results: Poor TA as measured by the H–S test was observed in 11.2% of the patients. Based on pharmacy refill data, there was a poor global TA rate of 30.3%, which was 33.3%, 26.6%, and 34.2% for oral antidiabetic, antihypertensive, and lipid-lowering drugs, respectively. Concordance between the two methods was poor. There was no relationship between the degree of disease control and TA as measured by the H–S test. Good TA measured based on pharmacy refill data for antidiabetic and antihypertensive drugs was associated with lower glycosylated hemoglobin and diastolic blood pressure values, respectively. Patients with good global TA showed lower glycosylated hemoglobin, diastolic blood pressure, and low-density lipoprotein cholesterol values. The multivariate analysis found good oral antidiabetic adherence to be associated to free pharmacy service; good antihypertensive drug adherence to the existence of comorbidities; and good lipid-lowering drug adherence to a history of ischemic heart disease, and a more experienced physician and/or female physician.Conclusion: Concordance between the two methods in assessing TA was low. Approximately one-third of the patients with type 2 diabetes mellitus presented poor TA in relation to antihypertensive, lipid-lowering, and antidiabetic medication. An improved TA was associated with a better control of the studied parameters. Comorbidities, such as ischemic heart disease and access to free pharmacy service, were identified as determinants of good TA.Keywords: medication adherence, determinants of adherence, diabetes mellitus, hypertension, hyperlipidemia, validation stud

The relationship between effectiveness and costs measured by a risk-adjusted case-mix system: multicentre study of Catalonian population data bases

<p>Abstract</p> <p>Background</p> <p>The main objective of this study is to measure the relationship between morbidity, direct health care costs and the degree of clinical effectiveness (resolution) of health centres and health professionals by the retrospective application of Adjusted Clinical Groups in a Spanish population setting. The secondary objectives are to determine the factors determining inadequate correlations and the opinion of health professionals on these instruments.</p> <p>Methods/Design</p> <p>We will carry out a multi-centre, retrospective study using patient records from 15 primary health care centres and population data bases. The main measurements will be: general variables (age and sex, centre, service [family medicine, paediatrics], and medical unit), dependent variables (mean number of visits, episodes and direct costs), co-morbidity (Johns Hopkins University Adjusted Clinical Groups Case-Mix System) and effectiveness.</p> <p>The totality of centres/patients will be considered as the standard for comparison. The efficiency index for visits, tests (laboratory, radiology, others), referrals, pharmaceutical prescriptions and total will be calculated as the ratio: observed variables/variables expected by indirect standardization.</p> <p>The model of cost/patient/year will differentiate fixed/semi-fixed (visits) costs of the variables for each patient attended/year (N = 350,000 inhabitants). The mean relative weights of the cost of care will be obtained. The effectiveness will be measured using a set of 50 indicators of process, efficiency and/or health results, and an adjusted synthetic index will be constructed (method: percentile 50).</p> <p>The correlation between the efficiency (relative-weights) and synthetic (by centre and physician) indices will be established using the coefficient of determination. The opinion/degree of acceptance of physicians (N = 1,000) will be measured using a structured questionnaire including various dimensions. Statistical analysis: multiple regression analysis (procedure: enter), ANCOVA (method: Bonferroni's adjustment) and multilevel analysis will be carried out to correct models. The level of statistical significance will be p < 0.05.</p