RCMAR Measurement Tools
Diabetes Quality-of-Life Measure (DQOL)
A. Jacobson, I. Barofsky, P. Cleary, L. Rand (1988)
Background and Development:
The DQOL was developed from a population of 192 subjects ages 13-39 with insulin dependent diabetes mellitus (IDDM – Type I Diabetes), but no major complications. Adolescents (age 13-17) comprised 56 of the 192 subjects. The DQOL questionnaire contains 46 items which the subjects rank on a 5-point Likert scale. The items on the questionnaire do not identify specific treatments to make it applicable to various methods of diabetes management. Furthermore, it is designed for ease of use by both administrators and users (adults and adolescents). Four subscales measure life satisfaction, diabetes impact, worries about diabetes, and social/vocational concerns. Reliability of the measure, as measured by Cronbach’s alpha, was tested separately for adults and adolescents and the total DQOL score rated extremely high for both groups (alpha=0.92). Individual subscales were good (alpha ranged from 0.66 to 0.88) with worry about diabetes (containing only 4 items) measuring the lowest (alpha=0.67 and 0.66 for adults and adolescents, respectively). Validity was measured by comparison with three established instruments: the Symptom Checklist-90-R (SCL), the Bradburn Affect Balance Scale (ABS), and the Psychosocial Adjustment of Illness Scale (PAIS). The total DQOL score and the satisfaction and impact scales consistently showed significant correlations with these three measures. Test-retest correlations of the DQOL were excellent for both adults and adolescents, ranging from 0.80 to 0.92 with high statistical significance.
Assessment of the Measure in Elderly Populations
The DQOL has been further evaluated in older populations of both Type I and Type II diabetics (Jacobson et al. 1994) with average ages of 44 and 60 years, respectively. Cronbach’s alpha for total score and three of the subscales were similar to their earlier study, but slightly lower for the Worry scale (0.47-0.49). This study also showed that the DQOL compares favorably to the SF-36, although they report that the SF-36 is less sensitive to lifestyle issues such as diet or treatment. However, Mannucci et al. (1996) comment that a number of the items are not appropriate for elderly populations.
Assessment of the Measure in Minority Populations
A Chinese translation of the DQOL was used to assess factors related to diabetes management in a group of NIDDM Chinese immigrants residing in the San Francisco, California area (Rankin et al. 1997). The overall scale and the four subscales retained their reliability. No other assessments have been made in minority populations.
Eiser et al. (1991) used the DQOL to measure the relation of QOL to demographic and disease variables in young adults (ages 15-25) with Type I diabetes. The use of an implantable pump versus injections to manage diabetes in IDDM patients resulted in no differences in QOL as measured by the DQOL (Haardt et al. 1994). In a survey of childhood-onset IDDM subjects who have been diagnosed with diabetes at least 25 years (average age 37) QOL decreased with increasing complications (Lloyd et al. 1992). The DQOL has been used to assess the effects of family environment (Trief et al. 1998) and work environment (Trief et al. 1999) on glycemic control and psychosocial adaptation in adults with diabetes. A pediatric version of the DQOL containing 59 items has been used to assess the prevalence of eating disorder symptoms in adolescent girls with IDDM (Striegel-Moore et al. 1992). The DQOL has been used to assess patient QOL changes following pancreas-kidney transplantation (Sureshkumar 2002).
Design Strengths and Weaknesses:
In a review of health outcome measures for diabetes Garratt et al. (2002) state that this instrument has good evidence for reliability, and internal and external construct validity. Although the DQOL has been tested and validated with Type II diabetics (Jacobson et al. 1994), it was designed specifically for Type I diabetics with intensive insulin treatment, and may have deficiencies with assessing the quality of life for NIDDM subjects (Mannucci et al. 1996). Furthermore, having been designed for a younger population, including a high percentage of adolescents, many of the items are not appropriate for elderly populations (Mannucci et al. 1996). The four subscales were based on conceptual distinctions by the original authors and not on factor analysis of the individual items. A factor analysis by Eiser et al. (1991) derived 3 new subscales with poor correlation with the original four subscales.
The DQOL is printed as an appendix to Jacobson et al. (1988).
Eiser, C., M. Flynn, E. Green, T. Havermans, R. Kirby, D. Sandeman, and J.E. Tooke (1991) Quality of life in young adults with Type 1 diabetes in relation to demographic and disease variables. Diabetic Med. 9, 375-378.
Garratt, A.M., L. Schmidt, and R. Fitzpatrick (2002) Patient-assessed health outcome measures for diabetes: a structured review. Diabetic Med., 19, 1-11.
Haardt, M.-J., J.-L. Selam, G. Slama, J.-P. Bethoux, C. Dorange, B. Mace, M.-L. Ramaniche, and F. Bruzzo (1994) A cost-benefit comparison of intensive diabetes management with implantable pumps versus multiple subcutaneous injections in patients with Type I diabetes. Diabetes Care 17, 847-857.
Jacobson, A., I. Barofsky, P. Cleary, and L. Rand (1988) Reliability and validity of a diabetes quality-of-life measure for the diabetes control and complications trial (DCCT). Diabetes Care 11, 725-732.
Jacobson, A.M., M. De Groot, J.A. Samson (1994) The evaluation of two measures of quality of life in patients with type I and type II diabetes. Diabetes Care 17, 267-274.
Lloyd, C.E., K. A. Matthews, R.R. Wing, and T.J. Orchard (1992) Psychosocial factors and complications of IDDM. Diabetes Care 15, 166-172.
Mannucci, E., V. Ricca, G. Bardini, and C.M. Rotella (1996) Well-being enquiry for diabetics: A new measure of diabetes-related quality of life. Diab. Nutr. Metab. 9, 89-102.
Rankin, S.H., Galbraith, M.E., and P. Huang (1997) Quality of life and social environment as reported by Chinese immigrants with non-insulin-dependent diabetes mellitus. Diabetes Educator, 23, 171-177.
Striegel-Moore, R.H., T.J. Nicholson, and W.V. Tamborlane (1992) Prevalence of eating disorder symptoms in preadolescent and adolescent girls with IDDM. Diabetes Care 15, 1361-1368.
Sureshkumar, K.K., T. Mubin, N. Mikhael, J.A. Kashif, D.D. Nghiem, and R.J. Marcus (2002) Assessment of quality of life after simultaneous pancreas-kidney transplantation. Am J. Kidney Diseases 39, 1300-1306.
Trief, P.M., W. Grant, K. Elbert, and R.S. Weinstock (1998) Family environment, glycemic control, and the psychosocial adaptation of adults with diabetes. Diabetes Care 21, 241-245.
Trief, P.M., C. Aquilino, K. Paradies, and R.S. Weinstock (1999) Impact of the work environment on glycemic control and adaptation to diabetes. Diabetes Care 22, 569-574.
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