Background
International Diabetes Federation (IDF) reported that 425 million people had diabetes as of 2017 worldwide in which this figure up from an estimated 382 million people in 2013.1 2 The number is expected to be almost double by 2030.3 Diabetes mellitus (DM) is prevalent throughout the world but is more common (primarily type 2) in the more developed countries. However, there is a significant increase in prevalence in low-income and middle-income countries like Ethiopia where most patients will probably be found by 2030.3 The rise of its incidence in developing countries follows the trend of urbanization and lifestyle changes, including but not limited to increasingly sedentary lifestyles, physically inactive, marked by increased intake of foods that are high energy-dense but nutrient-poor. IDF estimated that 14.2 million are living with diabetes in Africa.4
The proper use of antidiabetic medications over a sustained period and a recommended change of lifestyle are crucial for the success of glycemic control in the management of DM.5 Given the progressive nature of diabetes, many patients require complex medication regimens to achieve or maintain glycemic control. This is because most patients with DM are accompanied with other chronic comorbid conditions and yet, these chronic conditions required long-term use of medication which leads to a more complex medication regimen to such patients. Nearly 15% of patients require both insulin and oral antidiabetic medications to treat diabetes.6 Although complex medication regimens may aid some patients in achieving their glycemic control, such regimens may also decrease adherence and thus worsen glycemic control.7–9
Low adherence to prescribed antidiabetes medications accounts for 30%–50% of treatment failures, leading to worse treatment outcomes and which cause damages to vital organs.10 Besides, difficulties with medication therapy have a negative impact on the patients’ perception of their health status and quality of life.11 With advances in medicine and longevity, the burden of medication regimens has increased. As of 2010, individuals using five or more prescription drugs increased by 70% as compared with the previous decade.12
Medication adherence could be influenced by many factors, including some individual factors (eg, socioeconomic status, age, sex, and race) and some health system factors (eg, health literacy, convenience of pharmacy, and medication regimen complexity).13–22 Medication regimen complexity is a modifiable factor that affects adherence and clinical outcomes. The collaboration of pharmacists and other healthcare professionals has been effective in simplification of complex regimens to improve adherence and clinical outcomes.23 24
A simple, universal measure of medication regimen complexity is a count of prescribed medications. However, medication count is unlikely to be an adequate measure of regimen complexity because it does not address other regimen characteristics contributing to complexity, such as dosage forms, dosing frequencies, and usage directions. Besides, medication count may not include over-the-counter (OTC) medications, which in some patients can contribute significantly to medication complexity. Higher treatment complexity is associated with lower rates of optimal adherence.25 Previous studies showed, for instance, higher adherence to a once-daily than a twice-daily regime26 27 and a study using a composite score of drug administration, dosing frequency, and additional directions found that patients with low complexity scores were more often adherent than patients with high complexity scores.28 The result of a study which investigates the impact of Medication Regimen Complexity Index (MRCI) on glycemic control and medication adherence reported by Michael Pollack et al in 2010 revealed that treatment complexity has adverse effects on adherence and glycemic control.28 Moreover, the negative impacts of adherence on glycemic control have been established.29–31 There are a limited number of articles focusing on the evaluation of regimen complexity and its impact on adherence to antidiabetic treatment and glycemic control in developing countries like Ethiopia. A few studies in Ethiopia report that, being on an insulin drug regimen, consulting traditional healers, lack of financial resources, perceived side effects, experience depressive symptoms, and concerns about medications’ safety were cited as the common factors for poor adherence among type 2 DM (T2DM).32–34 A hospital-based cross-sectional study conducted at the University of Gondar Referral Hospital revealed that 64.7% of patients with DM had a poor level of glycemic control, as evidenced by HbA1c>7%. Furthermore, this study reported that being on insulin treatment and poor medication adherence were found to be associated with poor glycemic control among patients with T2DM.35 Results of few studies revealed that patients with DM with complex medication regimen experience poor clinical outcomes and quality of life.11 36 A cross-sectional survey conducted in Brazil by Samanta et al reported that patients with higher MRCI were associated with low scores in the physical, psychological, and overall quality of life domains.37 There are no data available regarding the impact of medication regimen complexity on medication adherence and glycemic control in Ethiopia so far. Therefore, the present study aimed at evaluating the complexity of medications and its impact on adherence and glycemic control among individuals with T2DM in Ethiopian general hospital.