Pharmacist-led Intervention in Treatment Non-adherence and Costs of Management Among Ambulatory Type 2 Diabetes and Hypertensive Patients in Southwestern Nigeria

The study involved adult T2D, hypertensive and those with the two diseases attending the cardiology and endocrinology out-patient clinics of the two tertiary hospitals [University College Hospital (UCH), Ibadan and Federal Medica Centre (FMC), Abeokuta, Nigeria].

Sample size determination

For the prospective phase, an average of 25 patients regularly attend the weekly medical out-patient endocrinology clinic of the two hospitals. This gives a total of 100 patients per month in each hospital, and for the 6-months study period gave an estimated population of 600 T2D per hospital. However, a maximum of 2 to 6 months clinic appointment is usually given to T2D in UCH, and a maximum of 3 months appointment in FMC, the appointment schedule was based on the extent of glycaemic control. Based on this information, an estimated T2D population for 4-months and 3-months was used to calculate the target sample size for UCH and FMC, respectively. Thus, considering the regular attendee of 100 patients per month in each of the hospital, a total of 700 T2D was used as estimated population to guide sample size determination using the Raosoft® sample size calculator at 95% confidence level and 5% margin of error (http://www.raosoft.com/samplesize.html). This gave a target sample size of 249 T2D participants to be enrolled for the study. Similarly, Average of 20 hypertensive patients regularly attend the weekly medical out-patient cardiology clinic of the two hospitals. This gives a total of 80 patients per month in each hospital, and for the 6-months study period gave an estimated population of 320 hypertensive patients per hospital. However, a maximum of 2 to 6 months clinic appointment is usually given to hypertensive patients in UCH, and a maximum of 3 months appointment in FMC, depending on the extent of control of the blood pressure. Based on this information, an estimated hypertensive patients population for 4-months and 3-months was used to calculate the target sample size for UCH and FMC, respectively. Thus, considering the regular attendee of 80 patients per month in each of the hospital, a total of 560 was used as estimated population to guide sample size determination using the Raosoft® sample size calculator at 95% confidence level and 5% margin of error. This gave a target sample size of 229 hypertensive participants to be enrolled.

Instrument descriptions The baseline questionnaire comprised sections A to F. Section A captured demographic data, section B contained modified International Physical Activity Questionnaire short-form (IPAQ-SF) (IPAQ-SF, 2002) and individual physical activity was calculated as metabolic equivalent task (MET) per week (http://www.ipaq.ki.se). IPAQ -SF instrument measures duration, frequency, intensity of physical activity in leisure-time, work, and doing household tasks in the past seven days. This short version consists of seven items including time spent in walking, vigorous activity, moderate activity, and sedentary activity weekly. Metabolic Equivalent Tasks (MET) values reported by patients were computed. To interpret the modified IPAQ-SF, according to WHO, an adult is expected to have minimum of 600 Metabolic Equivalents (MET) physical activities weekly. Participants were classified as non-adherent and adherent to exercise if he/she has less than 600 and above 600METs per week respectively.

Section C consisted of modified Perceived Dietary Adherence Questionnaire (PDAQ) developed by Assad et al., (2015), to measure patients' perception of dietary adherence. For these items, higher scores reflected higher level of adherence (Assad et al., 2015). However, items four and nine, indicated unhealthy choices (foods high in sugar or fat). For these items, higher scores reflected lower adherence. In computing the total PDAQ score, the scores for these two items were inverted. Although based on a weekly timeframe, it was anticipated that the PDAQ would reflect usual dietary patterns based on knowledge that most people consume similar foods from week to week (Assad et al., 2015). In this study, PDAQ was interpreted by classifying participants as adherent to dietary recommendations if they scored 51 (80%) and above, out of the 63 maximum obtainable score, while those who scored less than 51 (80%) were classified as non-adherent to dietary recommendations. Section D of the instrument contained the 4-items Medication Adherence Questions (MAQ) while section E explored reason(s) for non-adherence to medications, physical activity and dietary recommendations. Section F of the instrument contained the components of educational intervention to resolve non-adherence problems that were identified from the responses to questions in MAQ, IPAQ-SF and PDAQ among patients in the intervention groups. Where necessary, at least one to two clinic appointment was rescheduled to follow-up of the participants in the intervention group. The 6-months post-baseline evaluation employed the same questions in sections B, C, D and E to re-assessed participants in both control and intervention groups, to ascertain the possible change in adherence status to recommended medications, physical activity and dietary management.