Department of Family Medicine
Audit of Diabetes-Dependent Quality of Life (ADDQoL)
C. Bradley, C. Todd, T. Gorton, E. Symonds, A. Martin, and R. Plowright (1999)
Background and Development:
The ADDQoL contains 13 items which were designed to measure individuals’ perceptions of the impact of diabetes on their quality of life. The individual items take the form of: “If I did not have diabetes my (employment/social life/etc.) would be (a great deal better … a great deal worse).” Each item is scored on a 7-point scale (-3 to +3) and then the respondent indicates whether the item is very important, important, quite important, or not at all important (3 to 0) . The respondent is allowed to indicate if an item is not applicable to them and should be dropped from consideration. Scoring and importance are multiplied for the applicable items and averaged to determine the final score.
Internal reliability, as measured by Cronbach’s alpha (0.85) was excellent. The measure was designed for both insulin-dependent and non-insulin-dependent subjects. As a measure of the construct validity of the measure, insulin-dependent subjects generally scored lower (=greater impact) than non-insulin-dependent subjects, and the mean weighted score correlated significantly with the number of reported complications. In an attempt to validate the SF-36 and to make comparisons with the ADDQoL, Woodcock et al. (2001) found that the SF-36, although valid and reliable, was stronly affected by non-diabetic comorbidity in type-2 diabetics, supporting the complementary use of a diabetes-specific measure.
Assessment in Elderly Populations
This instrument has not been tested specifically on elderly populations, although the population in the original study (Bradley et al. 1999) had an average age of 58.5 years.
Assessment in Minority Populations
This instrument has not been tested with minority populations.
A study to evaluate whether a course teaching flexible intensive insulin treatment combining dietary freedom and insulin adjustment can improve both glycaemic control and QOL in Type I diabetics used the ADDQoL to measure QOL changes due to the education program (DAFNE Study Group 2002). A QOL difference was not apparent after six months in the program, but became significantly improved after one year. Severe hypoglycaemia and cardiovascular risk remained unchanged throughout the study.
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. It is useful for both insulin-dependent and non-insulin-dependent subjects. It allows the subject to judge the relevance or importance of each item and to eliminate non-relevant or non-important items from consideration before calculating the final weighted score. Having only 13 items the measure does not require a great deal of time to administer. No special training is required to administer the survey.
The ADDQoL questionnaire and scoring methodology (including weighting) are available in Bradley et al. (1999). More information is available from the author:
Dr. Clare Bradley (firstname.lastname@example.org)
Health Psychology Research,
Department of Psychology,
Royal Holloway, University of London,
Egham, Surrey, TW20 0EX UK
The reserach team is currently building a web site (www.hprinternational.com) which will present the questionnaire and provide an on line licensing process for non-commercial agreements. This site will also contain information about other measurement tools which this group is developing.
Bradley, C., C. Todd, T. Gorton, E. Symonds, A. Martin, and R. Plowright (1999) The development of an individualized questionnaire measure of perceived impact of diabetes on quality of life: the ADDQoL. Qual. Life Res., 8, 79-91.
DAFNE Study Group (2002) Training in flexible, intensive insulin management to enable dietary freedom in people with type 1 diabetes: dose adjustment for normal eating (DAFNE) randomised controlled trial. Br. Med. J., 325, 746-749.
Garratt, A.M., L. Schmidt, and R. Fitzpatrick (2002) Patient-assessed health outcome measures for diabetes: a structured review. Diabetic Med., 19, 1-11.
Woodcock, A.J., S.A. Julious, A.L. Kinmouth, M.J. Campbell (2001) Problems with the performance of the SF-36 among peole with type 2 diabetes in general practice. Quality of Life Res. 10(8), 661-670.