Factors Affecting Medication Non Adherence in Type 2 Sudanese Diabetic Patients

Background: Medications non-adherence is responsible for treatment failure and a reason of higher cost of medical care. It had been proved that, in general, diabetic patients are non-adherent to their treatment and only a small number of them were found to be adhering with all aspects of diabetic care. Objectives: To assess and evaluate the most common factors associated with medications adherence among Type 2 Diabetes Mellitus (DM) patients attending Ribat University Hospital Diabetic Clinic (RUHDC) Khartoum state, Sudan. Methods: Single Centre Descriptive cross sectional hospital based study was carried out among 351 patients using structured questionnaire and patients cards. Results: A total of 351 patients were recruited in the study; 65.8% were females. About 64.4% were on oral medications and 35.6% on insulin. Adherence to medications among total Type 2 DM patients was 45%. Main barriers to medication adherence were drugs unavailability (34.3%) and forgetfulness (30.7%). Medications knowledge was 41.2% for patients on oral medications and 38.4% for insulin users. Conclusion: Adherence to anti-diabetic drugs in this study was found to be sub-optimal but considered reasonable in comparison with that reported by many African countries. Poor medications knowledge, drug brand unavailability and forgetfulness were the main reasons for medications non adherence. Family support, improving healthcare system and changing patents’ behavior will be needed to improve medications adherence.


Introduction
Treatment of Type 2 Diabetes Mellitus (DM) is complex, cost-effective and requires recommendations that are tailored to fit with person's needs, culture and educational level [1] [2].Medications adherence, life style modifications and specialized multidisciplinary team are the cardinal keys of diabetes management.Medication adherence is defined as "the extent to which the patient takes his medications as prescribed" and this prescription should be based on agreement between the patient and his medical provider [3].Medications non-adherence is responsible for failure to attain positive clinical outcomes [4]- [7] and a reason of higher cost of medical care [3].On the other hand, each 25% improvement in adherent associated with reduction in HbA1c level and mortality rate [8].It has been proved that, in general, diabetic patients are non-adherent to their treatment and only a small numbers of diabetic patients have been found adherent with all aspects of diabetic care [9].The reasons for poor adherence are multifaceted and complex, and include, Patient-centered factors (such as age, sex, education, and forgetfulness), therapy-related factors (such as treatment complexity and side effects), healthcare system factors (such as drug availability and accessibility to healthcare), social and economic factors (such as cost of therapy, income and social support) [10]- [12].In Sudan 77% were found to be uncontrolled due to cost related factors [13].

Methods
A cross-sectional study was carried out at RUHDC.Ribat University Hospital is one of the biggest Teaching hospitals in Sudan.In addition to medical services to patients, the hospital renders service of teaching and research to many universities students and medical researchers.The questionnaire content was properly constructed from updated literature regarded diabetes medications adherence and validated by discussion with experts in diabetes management and medical research.Patients at first informed about the objectives of this study and then ten copies of a multiple-choice questionnaire were piloted among randomly selected Type 2 DM patients.After minor changes, the questionnaire distributed directly to patients attending to RUHDC during August 2012 and February 2013 at the study site, whilst patients' cards were also used to check or obtain some patients data.Newly diagnosed patients were taking medication less than 3 months were excluded.All 351 Type 2 DM patients taking medications for 3 months or more were enrolled in this study after obtaining full permission from researches authorities at Ribat University.Patients were interviewed face to face and asked "If they were taking their medications regularly" and also asked about "the exact time of medication use" Also information including socio-demographic characteristic and main reasons of medications non-adherence were obtained.Data were analyzed, using social package for social science (SPSS) version 16, to assess patient's answers.Descriptive and chi-square statistics were used.The values were considered to be significant at P ≤ 0.05.

Discussion
Medications adherence rates are low, among Type 2 DM patients, in both developed and developing countries.World health organization (WHO) stated that, adherence among patients suffering chronic diseases averages only 50% in developed countries and estimated to be much less in developing countries [3].A report from USA during the period 1999 to 2006 proved that adherence was very low [14].Medications adherence was low in our study and this result is slightly less than that carried in some developing countries, like ours, such as Ethiopia (51.3%) [15], and better than that done in Nigeria (40.1%) [16] and Egypt (38.9%) [17].Many studies revealed a difference in adherence between patients on oral medications and those on insulin.In retrospective studies, adherence was 62% and 64% for long-term and new-start insulin users, respectively [18].On the other hand Guillausseau P-J Y. et al. study found that only 46% were adherent to oral medications [19], whilst Rozenfeld Y. et al. study reported 81% for patients who had recently initiated oral therapy [20].In this study there was no significant adherence difference between patients on insulin or oral medications users.Many studies reported association between socio-demographic characteristics and adherence.Rasaq Adisa et al. [21] found female and professional with tertiary education were more adherent to their medications.Mohamed et al. study [17] from Egypt reported higher adherence was among, female (although not significant), younger and educated patients.Although high percent of adherence was among female, low education and older patients in our study, but we think we cannot give judge on the effect of age and sex because there was significant high difference in number of female and older age in our sample.However we agreed with effect of education because medications knowledge, in general, among our patients was poor.Numerous studies found significant relation between poor adherence and financial problems.Study in USA showed that 34% of patients stated that paying for medications was a reason for the lack of adherence [22].Yusuff et al. study in Nigeria [16] and Nasir et al. study in Ethiopia [15] specified lack of finance as major barrier for anti diabetic drug adherence; which institute 51.9% and 37.1% respectively.In our study drugs brand unavailability and forgetfulness were major barriers for medications adherence.Whilst financial reason as barrier in this study was weak (12.2%) and this because (83.8%) of our patients had insurance coverage.However insurance offer drug according to generic name, so sometimes many patients may stop their treatment for few days till they find the specific brand that they commonly use.

Conclusion
Adherence to anti-diabetic drugs in our study was found to be sub-optimal but considered reasonable when compared with that reported by many countries surrounding Sudan.Poor medications knowledge, drug brand unavailability and forgetfulness were the main reasons for medications non adherence.Family support and    psychological, together with patients education, interventions will change patients' behavior and improve adherence.Medical providers, mainly pharmacist, should inform patients that experiences in Sudan prove that the therapeutic effect of all anti-diabetic drug brands is accepted.

Limitation
Although Ribat University Hospital is one of the biggest hospitals in Sudan, conducting this study in single centre will not give the complete picture about medication non adherence among type 2 DM in Sudan as a whole.So generalized study funded by considerable organization or research institute is urgently recommended.Data were obtained by self-report questionnaire which may over estimated adherence, so further studies are recommended by using more accurate methods such as electronic measurement to assess medication adherence.

Figure 1 .
Figure 1.Patients' classification according to type of Medications.

Figure 3 .
Figure 3. Main Reasons for medications non adherence.

Table 1 .
Socio demographic characteristics in relation to adherence.

Table 2 .
Comparison between Types of Medications in respect to adherence and knowledge.