Quality of Life in Patients with Type 2 Diabetes: Application of WHOQoL-BREF Scale

Diabetes is one of the most important chronic diseases in population that occurs either when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin it produces. Type 1 diabetes known as insulin-dependent, juvenile or childhood-onset and Type 2 diabetes known as non-insulin-dependent or adult-onset. Type 2 diabetes comprises 90% of people with diabetes around the world, and is largely the result of excess body weight and physical inactivity (1). Diabetes and its complications may have negative effect on QoL of patients, but relatively little is known about it. QoL is defined by World Health Organization (WHO) as “an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns” (2). In order to study QoL, we must be able to measure it. In the world, many general instruments have been used to measure QoL. The World Health Organization QoL-BREF (WHOQoL-BREF) questionnaire is one of the instruments that is used to measure QoL in different patients groups (3-7). The WHOQoL-BREF questionnaire is available in many languages (8) and also it has been translated into Persian and then validated in Iran by Nedjat (9). Information on the QoL of diabetic patients is important for health policy makers and physicians in order to identify and implement interventional programs for improving the QoL of them. Some studies assessed QoL in diabetic patients and they suggest a decrease in their QoL (10-13). This study conducted in order to assess QoL of diabetic patients that they live in rural regions of Neyshabur as well as determine some factors associated with it with use of WHOQoL-BREF scale.

This cross-sectional study was conducted in 1847 patients with type 2 diabetes. The data were collected between April and July 2012, at the all rural regions of Neyshabur. Of all diabetic patients (n = 2224), three hundred and seventy seven persons were excluded from the study because of their avoidance to participate in the study (response rate: 83.05%). Individuals with diabetes were identified based on the lists available in the Neyshabur rural health centers. In this study for all study population provided informed consent after being acquainted with the purpose of study. Questionnaires have been filled by participants (except illiterate persons and some special situations) and all of them were informed that their responses would remain confidential. In this study, we made use of the WHOQoL-BREF questionnaire that was validated by Nedjat in Iran (9). The WHOQoL-BREF questionnaire contains 26 questions: two questions from the Overall QoL and General Health and 24 questions of satisfaction divided into four domains: 1. Physical Health, 2. Psychological Health, 3. Social Relationships, and 4. Environmental Health. The responses of each question are rated on a 5-point Likert scale and scored from 1 to 5. Raw scores in each domain were transformed to a 4–20 score according to guideline (8). The mean score of questions in each domain is used to calculate the domain score and finally they transformed linearly to a 0–100-scale (14, 15). Higher scores are associated with a higher QoL. Inclusion criteria applied in the study included: (a) having diabetes type 2, (b) residence in Neyshabur rurals regions (c) agreement to participate in the study. Data were analyzed with the use of SPSS16 software. Descriptive analyses were conducted including frequencies, percentages, ranges, means, and standard deviations (SD). The reliability of the WHOQoL- BREF domains was assessed using Cronbach's Alpha (0.70 and over were deemed acceptable) (16). We also assessed the reliability of the overall QoL. We examined the level of agreement between four domains of the WHOQoL- BREF with the use of Pearson’s correlation coefficient. t-independent test and multiple linear regression model (with backward method) were used to investigate the relation between participants' QoL and their characteristics including sex, age, BMI, education level, marital status, household income and distance from the city. In this study transformed scores were used for statistical analyses in all domains and P values less than 0.05 were regarded as significant.

Overall, 1847 diabetic patients were studied. Table 1 presents the characteristics of study population. The mean age of participants was 59.65 ± 12.3 yr (Rang: 30-97 yr). In this study majority of study population were female (sex ratio: 2.31). Cronbach’s alpha coefficient was applied to evaluate the internal consistency of WHOQoL-BREF scale and the four domains of it. The observed Cronbach’s alpha coefficient for all questions of WHOQoL-BREF was 0.93 and for each domain the values are: Physical health domain = 0.86, Psychological health domain = 0.78, Social relationship domain = 0.69 and Environmental health domain = 0.76. Table 2 displays correlations between four domains of WHOQoL-BREF; as observed; there were significant correlations between all domains (P < 0.05). As Table 3 displays, the total mean score of WHOQoL-BREF was 12.18 and among the different domains of it, the lowest and the highest mean and percentage (Fig1) of satisfaction were observed in Psychological health domain (Mean = 11.73; percentage: 48.39) and Social relationship domain (Mean = 12.66; percentage: 54.16) respectively. As Table 3 shows, the mean scores in three domains of QoL (Physical Health, Psychological Health and Social relationship) were significantly higher in men in comparison to women. Also, the mean scores of four domains and total of WHOQoL- BREF according to other independent variables (age, BMI, educational level, marital status, household income and distance from city) are presented in table 3. As Table 3 displays, after the use of Univariate test observed that there was significant relation between different states of some variables in four domains and total of WHOQoL- BREF (P < 0.05). Table 4 shows the results of Backward Multiple Linear Regression; it shows that sex, age, education level, marital status and household income are significantly associated with total WHOQoL. Education level, marital status and household income are associated with four domains of WHOQoL. Age is associated with Physical Health and Psychological Health domains.

This study was conducted in order to access information about QoL and associated factors among patients with type 2 diabetes in rural regions of Neyshabur. In this study it is observed that the overall mean score of QoL in diabetic patients is 12.18 (51.2%), indicating a moderate to low QoL in them. In Imayama’ study, which was conducted to investigate the determinants of QoL in adults with type 1 and type 2 diabetes it was observed that the mean of QoL scores was 54.8 in type 1 diabetes group and 54.7 in type 2 diabetic group (17). Among the four domains of WHOQoL- BREF, the highest mean score was observed in SR domain (social relationships, 12.66), implying that study population had relatively more satisfaction of their personal relationships and sexual activity and also social support. Moreover, the lowest mean score was observed in PSH domain (Psychological health, 11.73), indicating not very good bodily image, positive feelings, self-esteem, personal beliefs and concentration and also having more negative feelings.

In present study, after the use of multiple linear regression (as shows in table 4) it was observed that education level, marital status and household income were significantly associated with total and four domains of WHOQoL (P < 0.05). In study conducted by Monjamed, the results showed that QoL was significantly associated with education level of study population (diabetic persons) but no significance association was observed between QoL and marital status (18). In Baghiyani’ study conducted on 120 type 2 diabetic persons in Yazd, no significance association was observed between education level and QoL (19). In Glasgow’ study it was observed that less education and lower income are related to lower QoL in diabetic patients (20). In Jacobson’ study a pattern of relationships was observed between marital status and QoL, which indicated that divorced or separated persons experienced worse QoL than those who were married or single (21). In this study, we found that QoL is better among diabetic men than among diabetic women. Some factors may be associated with lower QoL in women as well as diabetes (e.g., having more depression or anxiety in comparison to men, pregnancy, delivery, milking and so on) that need to do more investigation. As the findings of Baghiyani Moghadam, Glasgow and Dias’ studies showed men had a better perception of QoL than women (19, 20, 22). In Russell and Akinci studies, it was observed that males had significantly higher QoL than females (20, 23). Also, in some studies it was observed that females had higher QoL than males (18, 24, 25).

Figure 1.

Comparison Transformed Scores of the WHOQoL- BREF in Total and its Four Domains

In this study observed that younger persons had significantly higher QoL than older persons. In Monjamed and Baghiyani Moghadam’ studies didn’t observed significance association between age of diabetic persons and QoL of them (18, 19). In Glasgow’ study observed that older diabetic people had lower QoL (20). As showed in some studies, increasing age of diabetic patients has been associated with reduced physical functioning, better mental health, increased resignation to chronic illness, and less tolerance for ambiguities of the disease (20, 26-29).

Overall, Neyshabur type 2 diabetic patients reported low to moderate QoL, which appears to be related to some factors, especially education levels, marital status and household income. The findings of the present study indicates that there is a special need in order to identify and implement appropriate interventions by Neyshabur health leaderships for achieving better management of diabetes and finally improving the relatively low level of QoL of diabetic patients that they live in rural regions of Neyshabur.