Terrence Steyer, M.D.
Chair, Department of Family Medicine
J.T. Fitzgerald, W.K. Davis, C.M. Connell, G.E. Hess, M.M. Funnell, R.G. Hiss (1996)
The DCP was developed as an instrument to assess social and psychological factors related to diabetes and its treatment. The questionnaire is self-administered and consists of 234 items including demographic information, self-care practices, and 116 questions divided into 16 profile scales with 4 to 19 questions per scale. It takes approximately 30 to 40 minutes to complete. The 16 profile scales assess control problems, social and personal factors, positive attitude, negative attitude, self-care ability, importance of care, self-care adherence, diet adherence, medical barriers, exercise barriers, monitoring barriers, understanding management practice, long-term care benefits, support needs, support, and support attitudes. In an initial study involving 1,017 patients in Michigan, internal reliability, as measured by Cronbach’s ?, was good to excellent, ranging from 0.60 to 0.95 for the profile scales. Significant differences were found between type I and type II diabetics for 6 of the 14 scales. Three scales (control problems, self-care ability, and self-care adherence) were significantly correlated with GHb level. A second study involving 576 patients again measured the reliability and validity of the DCP. Cronbach’s ? ranged from 0.66 to 0.94 in this set of patients. Significant correlations were found between many of the DCP profile scales and independent psychological and social measures.
In a study measuring the reliability and validity of the instrument in an elderly population (average age 63.4) with NIDDM, 8 of the 16 profile scales showed good to excellent reliability (Cronbach’s ? 0.60-0.95). The validity of the DCP was measured in comparison to the SF-36 and glycemic control. Correlations between DCP profile scales and SF-36 subscales were more often significant in the non-insulin using population than in the insulin using population. Significant correlations were found between selected DCP profile scales and glycemic control. An additional study with an elderly, type 2 diabetic population (average age 62) also showed good to excellent reliability (Fitzgerald et al. 1998). Cronbach’s ? for the 16 profile scales ranged from 0.68 to 0.97.
This instrument has been tested with a Black population of type 2 diabetics in the metropolitan Detroit area to confirm the reliability of the instrument (Fitzgerald et al. 1998). Cronbach’s ? for the 16 profile scores ranged from 0.70 to 0.97. No significant reliability differences were found between Black and White populations. The results of a two-way ANOVA suggest that insulin use has a greater impact than does ethnic background. Another study investigating the effects of ethnicity on DCP score showed an effect on only 3 of the profile scales (control, support, and support attitudes) (Fitzgerald et al. 2000).
Since many of the questions and profile scales deal primarily with insulin management, a study comparing the DCP with a global measure of health-related QOL (the SF-36) was conducted on the 8 profile scales which are appropriate for patients with NIDDM (Anderson et al. 1997). This study found good correlation between the two measures and with the number of complications for patients who have type 2 diabetes. In addition, the DCP has predictive validity regarding glycemic control. Using the DCP to assess QOL, another study, investigating the cognitive aspects of the disease and the burden of diabetes care management on behavior, found that specific health-related behaviors and perceptions of control do influence QOL (Watkins et al. 2000).
The DCP is an internally reliable and externally valid survey instrument. It has been tested in minority and elderly populations and has been shown to have no biases regarding these populations. With 234 questions and taking 30-40 minutes to compete it is a long survey tool. Since it is self-administered the length may hinder the completion of the survey by subjects. Response rates from mailed-in surveys typically were about 65%.
Researchers can find the Diabetes Care Profile (as well as some of the other University of Michigan Diabetes surveys) at http://www.med.umich.edu/mdrtc/. Select "Survey Instruments" from the menu. A letter of permission can also be obtained as well as the scoring formula. There is no cost to use the survey.
Anderson, R.M., J.T. Fitzgerald, K. Wisdom, W.K. Davis, and R.G. Hiss (1997) A comparison of global versus disease-specific quality-of-life measures in patients with NIDDM. Diabetes Care, 20, 299-305.
Fitzgerald, J.T., R.M. Anderson, L.D. Gruppen, W.K. Davis, L.C. Aman, S.J. Jacober, and G. Grunberger (1998) The reliability of the Diabetes Care Profile for African Americans. Evaluation & The Health Professions, 21, 52-65.
Fitzgerald, J.T., W.K. Davis, C.M. Connell, G.E. Hess, M.M. Funnell, and R.G. Hiss (1996) Development and validation of the Diabetes Care Profile. Evaluation & The Health Professions, 19, 208-230.
Fitzgerald, J.T., L.D. Gruppen, R.M. Anderson, M.M. Funnell, S.J. Jacober, G.Grunberger, and L.C. Aman (2000) The influence of treatment modality and ethnicity on attitudes in Type 2 diabetics. Diabetes Care, 23, 313-318.
Watkins KW, C.M. Connell, J.T. Fitzgerald, L. Klem, T. Hickey, and B. Ingersoll-Dayton, (2000) Effect of adults' self-regulation of diabetes on quality-of-life outcomes. Diabetes Care, 23(10), 1511-1515.