|Year : 2012 | Volume
| Issue : 7 | Page : 310-315
Blood glucose control and medication adherence among adult type 2 diabetic Nigerians attending a primary care clinic in under-resourced environment of eastern Nigeria
Iloh GU Pascal1, John N Ofoedu1, Njoku P Uchenna1, Amadi A Nkwa2, Godswill-Uko E Uchamma3
1 Department of Family Medicine, Federal Medical Centre, Umuahia, Abia State, Nigeria
2 Department of Public Health Technology, Federal University of Technology, Owerri, Imo State, Nigeria
3 Department of Anaesthesiology, Federal Medical Centre, Umuahia, Abia State, Nigeria
|Date of Web Publication||17-Jul-2012|
Iloh GU Pascal
Department of Family Medicine, Federal Medical Centre, Umuahia, Abia State
Background: Despite the evidence that goal blood glucose control reduces preventable emergency hospitalizations, the control of blood glucose has been variable in Nigeria. Aim: The study was designed to determine the blood glucose control and medication adherence among adult type 2 diabetic Nigerians attending a primary care clinic in under-resourced environment of Eastern Nigeria. Materials and Methods: A cross-sectional study was carried out on 120 adult type 2 diabetic patients who were on treatment for at least 3 months at the primary care clinic of Federal Medical Centre, Umuahia. A patient was said to have a goal blood glucose control if the fasting blood glucose was 70-130 mg/dL. Adherence was assessed in the previous 30 days using pretested, interviewer-administered questionnaire on self-reported therapy. Operationally, an adherent patient was one who scored 4 points in the previous 30 days. The reasons for non-adherence were documented. Results: The blood glucose control and medication adherence rates were 61.7% and 72.5%, respectively. Blood glucose control was significantly associated with adherence to treatment (P=0.025) and medication duration ≥3 years (P=0.045). The most common reason for non-adherence was financial constraints (P=0.033). Conclusion: Glycaemic control and medication adherence among the study population were good and should constitute logical targets for intervention.
Keywords: Adherence, Control, Nigeria, Primary care clinic, Type 2 diabetes, Under-resourced
|How to cite this article:|
Pascal IG, Ofoedu JN, Uchenna NP, Nkwa AA, Uchamma GUE. Blood glucose control and medication adherence among adult type 2 diabetic Nigerians attending a primary care clinic in under-resourced environment of eastern Nigeria. North Am J Med Sci 2012;4:310-5
|How to cite this URL:|
Pascal IG, Ofoedu JN, Uchenna NP, Nkwa AA, Uchamma GUE. Blood glucose control and medication adherence among adult type 2 diabetic Nigerians attending a primary care clinic in under-resourced environment of eastern Nigeria. North Am J Med Sci [serial online] 2012 [cited 2013 Dec 13];4:310-5. Available from: http://www.najms.org/text.asp?2012/4/7/310/98590
| Introduction|| |
Diabetes mellitus is a global clinical and public health problem.  In Nigeria, the prevalence rate of diabetes mellitus is about 1-7% of the population with over 90% of these being type 2 diabetes mellitus.  In recent years there has been increasing concern about the control of blood glucose among type 2 diabetic patients in Nigeria.  The benefits of goal glycaemic control have been documented in previous studies. ,,, The goal of diabetic therapy is to prevent acute illness and to reduce the risk of long-term complications. The reasonable objective of treatment is therefore to approach normal glycaemic excursions without provoking severe or frequent hypoglycaemia. The acceptable levels of glycaemic control have been defined using fasting plasma glucose of 70-130 mg/dL and HbA 1 c of 5-7%.  The fasting plasma glucose indicates the level of short term glycaemic control and an index of acute complications while the concentration of glycated haemoglobin is a reflection of average blood glucose concentration over the preceding 2-3 months and a mirror of long-term control. ,
Studies have shown that blood glucose control constitutes a risk factor for micro-vascular and macro-vascular complications of diabetes mellitus. ,,,, However, blood glucose control is determined by several factors such as patient-related, family-related, health professional-related and healthcare provider-related factors.  Among the patient-elated factor of diabetic management is adherence with anti-diabetic medication. , Adherence to anti-diabetic treatment is therefore one of the greatest challenges of diabetic management and has been shown to be an important factor for blood glucose control in treated type 2 diabetic patients.  Adherence to medication refers to the degree to which the patient conforms to treatment as prescribed.  Several methods of measuring adherence with medication have been described, ,,, but there is no gold standard for precise measurement of adherence.  More so, several medication adherence survey scales at the point of care have been documented such as Modified Morisky Adherence Predictor Scale (MMAPS), Medication Adherence Rating Scale (MARS), Brief Medication Questionnaire (BMQ), Self Efficacy for Appropriate Medication use Scale (SEAMS) and Hill-Bone Compliance Scale (HBCS).  However, there is no gold standard medication adherence scale or questionnaire tool. 
Adherence to chronic disease management such as diabetes mellitus is reportedly variable.  A systematic review of adherence to medication for diabetic patients showed that the average adherence to oral hypoglycaemic agents ranged from 36% to 93%.  However, in under-resourced countries such as Nigeria, adherence rate and blood glucose control may even be lower. In order to provide necessary health services for management of diabetes mellitus in primary care facilities in Nigeria, clinicians should identify and determine the prevailing level of blood glucose control and factors responsible for poor blood glucose control. This study therefore provides an additional evidence of the contribution of adherence factors on the growing problem of goal blood glucose control in Nigeria. It is against this background that the researchers were motivated to study blood glucose control and medication adherence among adult type 2 diabetic Nigerians attending a primary care clinic in under-resourced environment of Eastern Nigeria.
| Materials and Methods|| |
Ethical certificate was obtained from the Ethics Committee of the hospital. Informed consent was also obtained from respondents included in the study.
This was a clinic-based cross-sectional study carried out on 120 diabetic patients from April 2011 to December 2011 at the department of Family Medicine of Federal Medical Centre (FMC), Umuahia, a tertiary hospital in Umuahia, Abia State, Eastern, Nigeria.
Umuahia is the capital of Abia State, South-East Nigeria. The State is endowed with abundant mineral and agricultural resources with supply of professional, skilled, semi-skilled and unskilled manpower. Economic and social activities are low compared to industrial and commercial cities such as Onitsha, Port Harcourt and Lagos in Nigeria. Until recently, the capital city and its environ have witnessed an upsurge in the number of banks, hotels, schools, markets, industries, junk food restaurants in addition to the changing dietary and social lifestyles.
FMC, Umuahia is located in the metropolitan city of Umuahia. It is a tertiary hospital established with the tripartite mandate of service delivery, training and research and serves as a referral center for primary and secondary public health institutions as well as missionary and private hospitals in Abia State and neighboring states of Imo, Ebonyi, Rivers and Akwa Ibom States of Nigeria. The department of Family Medicine serves as a primary care clinic within the tertiary hospital setting of the Medical Centre. All adult patients excluding those who need emergency health care services, paediatric patients and antenatal women are first seen at the department of Family Medicine where diagnoses are made. Patients who need primary care are managed and followed up in the clinic while those who need other specialists care are referred to the respective core specialist clinics for further management. The clinic is run by consultant family physicians and postgraduate resident doctors in Family Medicine.
Inclusion and exclusion criteria
The inclusion criteria were adult diabetic patients aged ≥18 years who gave informed consent, had been on outpatient treatment for diabetes mellitus for at least 3 months in the clinic and had recorded at least three clinic visits (recruitment visit, penultimate visit before the end of study and end of study visit). This was to ensure that the study population were familiar with prescribed oral hypoglycaemic medications. The exclusion criteria included critically ill patients, diabetic hypertensives, diabetic patients who were on insulin medication. The eligible patients were consecutively recruited for the study.
Sample size determination
Sample size estimation was determined using the formula  for estimating minimum sample size for descriptive studies when studying proportions with entire population size <10,000 using estimated population size of 200 adult diabetic patients based on the previous annual diabetic patients attendance records at Family Medicine clinic of the hospital. These 200 adult diabetic patients excluded other diabetic patients referred to and being followed up in other respective medical outpatients' clinic in the Medical Centre. The authors assumed that 50% of the adult diabetic patients would have good blood sugar control rate and adhere with treatment, at 95% confidence level and 5% margin of error. This gave a sample estimate of 132 patients. However, selected sample size of 120 adult diabetic patients was used based on the proposed duration of the study.
| Methods|| |
Adherence was assessed by the use of pretested, interviewer-administered questionnaire on 30 days self-administered and reported therapy (SAT). Patients were seen at the recruitment visit, penultimate visit before the end of study and then at the end of the study visit. At the end of study visit, the adherence section of the data collection tool was administered. The information collected at the end of study visit included: (i). How many times per day do you take your blood glucose medication? (ii). How many tablets do you take specific to your diabetic condition? (iii). How often do you take your blood glucose medication (all-times, most-times, some-times, rarely, never). (iv). How many dose(s) of your anti-diabetic drugs have you missed in the previous one month? v. How many of your previous blood glucose medication is remaining after the previous one month visit? Adherence was graded using an ordinal scoring system of 0-4 points developed by the authors from the review of literature ,,, as follows all-times=4 points, most-times=3 points, sometimes=2 points, rarely=1 point, never=0 point. Those that scored 4 points indicated adherence while those that scored 0-3 points meant non-adherence. The reasons for non-adherence were documented for those who scored 0-3 points.
Pretesting of the adherence section of the data collection tool was done internally at the Family Medicine clinic of FMC Umuahia, Eastern Nigeria and externally at Family Medicine clinic of FMC, Owerri, Eastern Nigeria. Five diabetic patients of FMC, Umuahia were haphazardly used for the pre-testing of the questionnaire which lasted for one day and five diabetic patients were used in FMC, Owerri. The pretesting was done to assess the applicability of the questionnaire tool internally and externally. All the patients used for the pretesting of the questionnaire instrument gave valid and reliable responses confirming the clarity and applicability of the questionnaire tool and questions were interpreted with the same meaning as intended. The questionnaire was administered by three resident doctors who were trained and recruited for the study. The questionnaire was administered once to each eligible respondent at the end of study visit.
The baseline fasting blood glucose was recorded at the time of recruitment for each patient (recruitment visit), subsequent fasting blood glucose was measured at penultimate visit before the end of study visit and then at the end of study visit. The duration of diabetes and number of anti-diabetic drugs and the reasons for non-adherence with anti-diabetic medication were documented. Diagnosis of diabetes mellitus was based on venous plasma glucose of ≥126 mg/dl after an overnight fast between 8.00 hours to 10.00 hours which was confirmed by a repeat test on second clinic visit.  The basic demographic variables of age, sex, marital status, education and occupation were also documented.
Operationally, a patient was defined to have goal blood glucose control if his or her fasting blood glucose at the end of study visit was between 70 and 130 mg/dL. An adherent patient was defined as one who had a score of 4 points (took the prescribed doses of anti diabetic drugs all-times) in the previous 30 days by the end of the study visit.
The results generated were analyzed using software Statistical Package for Social Sciences (SPSS) version 13.0, Inc. Chicago, IL, USA for the calculation of percentages for categorical variables and mean for continuous data. Means with standard deviations of continuous variables were generated where appropriate. Percentages and frequencies were compared by Chi-square and Student-t-test served to compare means. The level of statistical significance was set at P<0.05.
| Results|| |
The age of the type 2 diabetic patients ranged from 27 years to 81 years with mean age of 36.8±5.4 years. There were 45 (37.5%) males and 75 (62.5%) females with male to female ratio of 1:1.7 [Table 1].
Eighty-seven (72.5%) out of 120 patients were adherent while thirty-three (27.5%) were not adherent. Of the 74 patients who had goal blood glucose control, sixty-eight (91.9%) were adherent while six (8.1%) were not adherent. The blood glucose control rate was significantly higher in those that adhere to anti-diabetic medication when compared with non-adhering patients (χ2 =5.06, df=1, P value=0.025) [Table 2].
|Table 2: Association between adherence with medication and plasma glucose control|
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Thirty-seven (30.8%) patients had been diabetic for less than 3 years while eighty-three (69.2%) was diabetic for 3 years and more. Of the 74 patients that had goal blood glucose control, sixty-one (82.4%) had been diabetic for 3 years and more while thirteen (17.6%) were diabetic for less than 3 years. The difference between the two groups was statistically significant (χ2 =3.11, df=1, P value=0.045) [Table 3].
|Table 3: Relationship between duration of anti-diabetic medication and plasma glucose control|
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The most common reason adduced for non-adherence with medications by the diabetic patients was financial constraints (30.7%). Other reasons included forgetfulness (26.1%), feeling of wellbeing (21.6%), herbal remedies (12.5%) and advice by spiritual leaders (9.1%). This relative difference was statistically significant (χ2 =4.75, df=4, P value=0.033) [Table 4].
| Discussion|| |
The blood glucose control of 61.7% in this study is higher than 34.3% reported in Enugu, south-eastern Nigeria,  43.8% reported in Ibadan south-west Nigeria in 2008 by Yusuf et al. and 41.8% reported in Ethiopia.  However, the blood glucose control in this study is lower than 65.7% reported in a different study in Ibadan, south-west Nigeria in 2009 by Adisa et al. The findings of this study corroborate previous reports that adequate blood glucose control rates are low in Nigeria and occur only in a fraction of treated diabetic patients. ,, Although adequate blood glucose control does not completely obviate the risk of developing chronic complications of diabetes mellitus but it is vital for clinicians attending to diabetic patients to be aware of the variability of the blood glucose control rates in order to determine appropriate interventional strategies since poor glycaemic control constitute risk factor for diabetic complications. Thus, it is not enough to prescribe anti-diabetic medications during clinical encounter with diabetic patients but regular assessment of the level of control should be the focus of quality care rendered to diabetic patients in Nigeria. This will enable adult Nigerians with type 2 diabetes mellitus harness from the life saving benefits of anti-diabetic medications.
This study has demonstrated that blood glucose control was significantly higher among patients that adhered with their anti-diabetic medication compared with their non-adherent counterparts. The adherence rate of 72.5% in this study is higher than adherence rate of 60.2% reported in Ibadan, south-west Nigeria in 2009 by Adisa et al. and 51.3% reported in Ethiopia.  The adherence rate in this study is lower than 93% reported in another study in Ibadan south-west Nigeria in 2008 by Yusuf et al. The finding of this study has demonstrated the contribution of adherence factor for blood glucose control among the study population. The adherence rate of 72.5% in this study relatively translated to the accomplishment of the target glycaemic control of 61.7% positing that adherent patients had better glycaemic control than the non-adhering patients. Thus, if diabetic patients adhere with their appropriately prescribed anti-diabetic medication glycaemic outcome will be expectedly improved.  Clinicians attending to type 2 diabetic patients should inquire rationally for medication adherence at every clinical encounter with diabetic patients. This will prevent the clinician from attributing lack of response to medications as therapeutic failure rather than medication adherence problems. This assumption has resulted in the clinical decision of increasing the dose of the medications, changing the medication or adding another anti-diabetic drug. The magnitude of this practice is better imagined than seen and will not favor attainment of clinically therapeutic outcome among type 2 diabetic patients.
Blood glucose control was significantly associated with the duration of diabetic condition. This finding is similar to the report from United States of America.  The finding of higher blood glucose control rate among patients who had their diabetic condition 3 years and more could be attributed to their increasing contacts with the hospital and other health facilities where there is repetitive instruction on medication adherence. These patients with longer duration of anti-diabetic medication by virtue of their frequent contacts with health facilities and health professionals are also more likely to be aware of the acute and chronic complications of uncontrolled blood glucose. In addition, it could be a reflection of wider social interaction with other diabetic patients on anti-diabetic medication adherence.
Although the factors responsible for non-adherence to medication in this study are variable, this study observed that the most common reason adduced by non-adhering type 2 diabetic patients was financial constraints. This reason is similar to the reports from Ibadan , and Ethiopia.  This finding has showcased the healthcare costs involved in the management of type 2 diabetic patients. Financial variables both direct and indirect costs of care have been reported to influence medication adherence among diabetics in Nigeria , and Ethiopia.  Cost of diabetic care therefore plays a vital role in anti-diabetic medication adherence and invariably blood glucose control. , Of great concern is the relatively high cost of newer oral hypoglycaemic agent especially the fixed dose combination formulation which has been documented to improve medication adherence. These patients lived on either fixed or variable daily or monthly earnings. However, due to life competing financial demands they may not be able to afford the cost of their medications. Non-adhering patients would invariably have a drug free period pending when they are able to purchase their medications. The adoption of variable cost reduction strategies and subsidizing the cost of anti-diabetic medication by Nigerian government and its collaborating agencies will improve the affordability of anti-diabetic medications in the country. This may not be practicable in an under-resourced Nigerian nation if there are no political will for the health of diabetic Nigerians especially those who could not afford the cost of diabetic care. Non-adherence with medication has negative consequences not only for the patients but also for the clinicians, healthcare delivery system and the Nigerian nation. Clinicians should therefore be aware of these subtleties because they can influence the quality and quantity of care delivered to these patients.
As the case detection rates of type 2 diabetes mellitus increase in adult Nigerians achieving blood glucose control to target has become an important management challenge. The management of diabetes mellitus ensures normal fasting blood glucose levels necessary for short-term and long-term control and reduction of acute and chronic complications of diabetes mellitus. Non-achievement of clinical blood glucose targets is therefore of phenomenal importance and can lead to increase hospital visits, preventable emergency admissions and deaths. Among the factors responsible for the type 2 diabetic management challenge is adherence with medication amongst other diverse factors driving goal blood glucose control. This study therefore calls for improved management of type 2 diabetes mellitus through inquiring for medication adherence during clinical consultation as well as strengthening the quality of diabetic care.
The limitations of this study are recognized by the researchers. First and foremost, the sample for the study was drawn from family medicine clinic of the hospital. Hence, the findings of this study may not be general conclusions regarding diabetic patients attending medical outpatient clinics of the department of internal medicine of the hospital. Secondly, the limitations of using fasting plasma glucose to assess chronic glycaemia and long-term complications of diabetes mellitus are also recognized by the researchers. Admittedly, fasting plasma glucose is predictive of acute glycaemia and day to day variability of blood glucose. However, local Nigerian studies have shown strong, significant positive correlations of HbA 1 c and fasting plasma glucose among Nigerian diabetics implying that fasting plasma glucose could be a good useful surrogate for chronic glycaemia in Nigeria. , Of great concern was non-availability of HbA 1 c assay in the study center. However, this study gave some useful insight into the magnitude of the glycaemic control among the study population. This study therefore provides useful baseline information for consultative, comparative and future research purposes in the study center. Furthermore, the limitations imposed by the self-reported measure of adherence for the study are recognized by the authors. In addition, the sample size for the study was relatively small, but this was the number of patients seen within the proposed duration of the study.
| Conclusion|| |
Glycaemic control and medication adherence among the study population were above average and should constitute logical targets for intervention. There is need to consider adherence factors alongside other multi-factorial determinants of goal blood glucose control during clinical encounter with diabetic patients in the study area.
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[Table 1], [Table 2], [Table 3], [Table 4]