Medications Adherence and Associated Factors among Patients with Type 2 Diabetes Mellitus in the Gaza Strip, Palestine

Adherence to the medical regimen continues to rank as a major clinical problem in the management of patients with essential hypertension, as in other conditions treated with drugs and life-style modification. This article reviews the psychometric properties and tests the concurrent and predictive validity of a structured four-item self-reported adherence measure (alpha reliability = 0.61), which can be easily integrated into the medical visit. Items in the scale address barriers to medication-taking and permit the health care provider to reinforce positive adherence behaviors. Data on patient adherence to the medical regimen were collected at the end of a formalized 18-month educational program. Blood pressure measurements were recorded throughout a 3-year follow-up period. Results showed the scale to demonstrate both concurrent and predictive validity with regard to blood pressure control at 2 years and 5 years, respectively. Seventy-five percent of the patients who scored high on the four-item scale at year 2 had their blood pressure under adequate control at year 5, compared with 47% under control at year 5 for those patients scoring low (P less than 0.01).

Much controversy exists regarding proper methods for the selection of variables in confounder control. Many authors condemn any use of significance testing, some encourage such testing, and other propose a mixed approach. This paper presents the results of a Monte Carlo simulation of several confounder selection criteria, including change-in-estimate and collapsibility test criteria. The methods are compared with respect to their impact on inferences regarding the study factor's effect, as measured by test size and power, bias, mean-squared error, and confidence interval coverage rates. In situations in which the best decision (of whether or not to adjust) is not always obvious, the change-in-estimate criterion tends to be superior, though significance testing methods can perform acceptably if their significance levels are set much higher than conventional levels (to values of 0.20 or more).

In health care research, the patient-doctor relationship as perceived by the patient is considered important. Our aim was to develop and validate a questionnaire that assesses the Patient-Doctor Relationship, the Patient-Doctor Relationship Questionnaire (PDRQ-9). The PDRQ-9 was developed out of the Helping Alliance Questionnaire of Luborsky, a scale that measures the therapeutic alliance in psychotherapy. Its psychometric qualities and validity in general practice were assessed, with the collaboration of 110 general practice patients and 55 patients in an Epilepsy Clinic. Principal components analysis demonstrates a two-factorial structure, one related to the doctor, and one related to the medical symptoms of the patient. Both show high reliability but as the second factor explains only 9% of the variance, it is eliminated from the questionnaire. The PDRQ-9 provides researchers a brief measure of the therapeutic aspects of the patient-doctor relationship in the primary care setting. It is a valuable tool for scientific and practical purposes involving the monitoring of the patient-doctor relationship.