Introduction

A report produced from the United States revealed that the major causes of death nowadays are chronic diseases [1,2,3]. It is clear that diabetes mellitus is one of the chronic non-communicable diseases that is plaguing both developed and developing countries at an alarming rate.

It is projected that the prevalence of diabetes globally will reach 380million by the year 2025 and that developing countries will be a major contributor to this increase [4,5].

Diabetes mellitus was once regarded as a disease of the affluent but is now vastly visible as a growing health problem in developing economies as almost 80% of diabetes deaths occur in low and middle income countries [5], of which Nigeria is one.

The National standardized prevalence rate of diabetes mellitus in Nigeria is 2.2%, while the crude prevalence rate is 7.4% in those aged 45 years and above who live in urban areas [6].

Diabetes mellitus is a demanding disease that affects a person’s health- related quality of life, a person’s ability to function and to desire satisfaction from doing so [7,8,9]. People with diabetes are constantly reminded of the disease on a daily basis, they have to eat carefully, exercise, test their blood glucose and based on the result decide when to schedule their next meal or medication. Furthermore, they often have to stop and check for symptoms of hypo or hyperglycaemia as well as deal with the fears of the possibility of complication of the disease.

Quality of life (QoL) is of central concern in evaluative research and improved quality of life is probably the most desired outcome of all healthcare policies ^{[10]. Quality of life has been defined as a “descriptive term that refers to people’s emotional, social and physical well being and their ability to function in the ordinary tasks of living” [11]. It could also mean the “degree to which a person enjoys the important possibilities of her/his life” [12], further still, quality of life has been defined as “individuals’ perception of their position in life in the context of the culture and value system in which they live and in relation to their goals, expectations, standards and concerns” [13]. These different definitions of quality of life stem from the multi –disciplinary use of the term. Another reason is the fact that life itself is complex and its importance to every individual is highly subjective. According to Farquahar “there are four main types of definition; global, component, focused, and combinational. The global is the most commonly used in defining quality of life. It allows for encompassing many different facets of the quality of life, however, it over generalizes and does not allow enough specificity of the major components to use it practically. The component definition attempts to break down the quality of life into specific elements in terms of dimensions and characteristics dependant on specific purposes, such as research topics and measurement for long-term project or policy. The limitation of the component approach is the reliability and validity of each component in the measure of quality of life. Focused definitions use only one or a small number of components to define the quality of life. This component approach is often used to define a very specific quality of life, such as that of a cancer patient, or one in hospice care. The drawback to this is that it is a very narrow definition and in some cases authors use it too broadly and attempt to extend it into a broader interpretation of the quality of life. The final version, the combination or hybrid, is created by combining global and component types. This includes the attendant advantages and disadvantages of both” [10].}

However, there is a consensus among researchers that an individual’s happiness and satisfaction with life are the two major building blocks in defining quality of life [14]. Health related quality of life (HRQoL) on the other hand include domains (aspects) of life that improve when a treatment option is successful. A clinically significant change in HRQOL is indicated by a decline in a domain that leads a physician or health care provider to alter a medication or medical treatment. HRQOL domains minimally include functional status (e.g., whether a patient is able to manage a household, use the telephone, or dress independently), mental health or emotional wellbeing (e.g., depressive symptoms, positive affect), social engagement (e.g. involvement with others, engagement in activities), and symptom states (e.g., pain, shortness of breath, fatigue). These domains represent typical outcomes in medical and social science research [15].

Numerous studies have been done to evaluate the effect of diabetes mellitus on the sufferer’s quality of life in the developed world [18]. In contrast, studies relating to the health-related quality of life of patients with diabetes in developing countries are limited.

This study is therefore aimed at assessing the health related quality of life of patients with diabetes mellitus and to evaluate the impact of the disease on their physical health, social relationship, psychological health and environment, in comparison with control subjects without diabetes mellitus.

Methods

Setting

Sample

Questionnaire

Statistical Analysis

Results

Characteristics of the Sample

Demographic information for the two groups is shown in (Table 1). There were more males in the diabetic and control groups. Diabetic patients were more often separated 6 (5.4%) and divorced 2(1.8%) compared to the control group in which there was no case of separation or divorce in marriage.

Patients with diabetes had a mean age of 59.0 years (range: 31-80 years) compared to the control group that had a slightly lower mean age of 53.52 years (range: 31-80 years). Chi-square test for trend showed a significant association between the age of both the diabetic patients and the control group. (X²=12.74, df=4, P=0.0004)

There was no statistically significant difference in educational level between the diabetic patients and the control group. (X²=0.644, df=1, P=0.4205). The male diabetic patients had a significantly longer duration of the disease 8.62  6.77 years compared to female diabetics; 5.44  5.22 years (p=0.0059).

Cronbach’s alpha for the 26 questions for both patients with diabetes and the control group was found to be 0.797 and 0.893 respectively.

Figure 1

TABLE 1. Demographics of Diabetic patients and Control

Evaluation of the Health Related Quality Of Life (HRQoL)

Health-related quality of life of diabetic patients was significantly lower than that for controls in all the domains except for environment domain where there was no significant difference (P=0.6478) (Table 2).

Figure 2

Table 2. Domain scores of WHOQoL-BREF for diabetic patients and control

Also in the sub analysis for diabetic patients using gender as a variable, there was no significant difference in HRQOL between diabetic males and females in all the domains. Patients treated in Owen-Jackson Obaseki clinic showed no statistically significant difference in HRQOL in all the domains when compared to patients receiving treatment from UBTH, except also in the environment domain where the p-value was 0.0044 (Table 3).

Patients’ complications and co morbidity did not result in any statistically significant difference in HRQoL in all the domains when compared to patients without complications and co morbidity.

Figure 3

Table 3. Domain scores for diabetic patients from Owen-Jackson clinic and UBTH

Discussion

The health-related quality of life in a cross-section of diabetic patients receiving treatment in UBTH and Owen-Jackson Obaseki clinic was studied in comparison to gender and age similar non-diabetic controls of similar age and gender distribution from the same geographical location and social-cultural environment.

We found that the overall perception of health-related quality of life in the health of patients with diabetes mellitus was lower in comparison with the non-diabetic control group. Overall, diabetic patients had a statistically significant lower mean HRQoL score in three of the four domains (Physical health, Psychological and Social relationship). This lower mean score could be attributed to the burden the disease places on them as a result of its demanding nature in management.

The social relationship domain had the lowest mean score in HRQoL of our patients. This domain assesses personal relationships, social support and sexual activity; of these three, the subjects were least satisfied with the sexual functioning component. Changes in sexual function is a common problem with aging, however, diabetes mellitus predisposes one to early onset and increased severity of these problems. Sexual dysfunction such as erectile dysfunction, impairs quality of life, and is associated with depression, increased anxiety and poor self-esteem in affected patients [22].Sexual dysfunction in diabetes affects both male and female diabetics and this invariably affects the patient’s personal relationships and family life. The low mean score in HRQoL of our patients suggests to a very large extent, a high degree of dissatisfaction to the items in this domain. This finding however differs from that of a previous study by Awadalla et al which reported no difference in the score of patients with diabetes in relation to a general population on the social relationship domain [5]. It is worthy of note that Awadalla’s sample of patients with diabetes had a good level of social support in the sense that they had strong family care giver support system. It has been shown that the family is a major source of support and the stronger the family support the better the psychological adjustment of the patient to the disease [23].

The environment domain had the highest mean score (meaning better quality of life) than other domains in both diabetic participants and the control group. Both groups were affected equally. Environment domain assesses physical safety and security, financial status, the physical environment in relation to pollution, noise, traffic, climate and conditions of living place. The import of this result is that the environment affected the HRQoL of the patients with diabetes and control groups equally. One reason for this could be because the participants with diabetes in the study were in stable condition and did not require any special adjustment of the environment for normal living hence they were not more significantly adversely affected by the environment than the control group. Related studies have reported similar findings [24, 25], the authors concluded that the environmental conditions affected HRQOL of diabetic patients and controls in a similar way. However, in this same domain patients receiving treatment in UBTH had a statistically significantly higher mean score when compared with those in Owen–Jackson Obaseki clinic. This difference may have resulted from the disparity in the social status of the patients. Patients attending Owen-Jackson were more likely to be of poorer financial status and thus were also less likely to be able to afford accommodation in areas of healthy environment hence their worse perceived HRQoL score in this domain.

Several studies have demonstrated that diabetes in the presence of complications has strong negative impact on the HRQoL of patients [26, 27]. This is because diabetes complications especially macrovascular complications such as myocardial infarction, angina , stroke and heart failure can affect almost all aspects of life including mobility, usual activities and perception of health [28]. However, in our study, presence of complications and other illnesses was not linked to poor HRQoL, a similar finding has been reported by Kolawole et al [29]. The reason for this finding in our study may be due to the fact that none of our diabetic subjects had any obvious end-stage complications which have been shown to have the greatest perceived burden on quality of life [30]. Another possible explanation is the fact that complications are less likely to have a high impact on the quality of life of older diabetics to which our sample fits than younger diabetics who invariably have less comorbidity and have not adjusted to the idea of accepting lesser health [31]. Nonetheless there is a need to validate this finding in patients with documented complications rather than patients’ reported complications. It is quite possible that what our diabetic subjects perceived and reported to be complications may actually not be clinically significant.

Limitations in this study include the relatively small sample size and the failure to consult patient’s medical records to confirm complications and comorbidities rather than subjects self-report which is fraught with ambiguities, exaggeration and recall bias [32, 33], may have affected the findings of this study.

The strength of this study lies in its setting in two centres that provide care for different socio- economic classes of diabetic patients. This study also adds to the limited studies which provide this type of baseline data and information on HRQoL for diabetic patients.

Conclusion

In this study the reported HRQoL of patients with diabetes was found to be lower than the control group in all domains except the environment domain. The social relationship domain had the worst impact on the patients and in this domain the patients were least satisfied with the component that assessed their sexual life. In order to improve the HRQoL of these patients we recommend that physicians and other care providers should thoroughly assess their patients with regard to their social relationships particularly their sexual life with a view to resolving any clinical problems they may have in these areas. Careful monitoring and tight glucose control is also recommended as this can prevent or delay complications such as sexual impotence which is a major concern of the patients. We suggest further studies to evaluate the impact of sexual dysfunction on the HRQoL of patients who have sexual dysfunction but good family and other social relationships.