Performance of the RAND-12 and SF-12 summary scores in type 2 diabetes.
OBJECTIVE
To compare the performance of the RAND-12 and SF-12 physical and mental health summary scores, in a sample of people with type 2 diabetes, in distinguishing groups of differing disease severity.


METHODS
Summary scores from RAND-12 and SF-12 were compared between known subgroups defined in terms of treatment intensity, duration of diabetes, time lost from work and emergency room visits for diabetes. Multiple regression analyses were used to compare known groups.


RESULTS
Statistically significant and clinically important differences were observed across comparisons of the RAND-12 physical health composite (PHC), that were not apparent on the physical component score (PCS-12). RAND-12 mental health composite (MHC) scores were statistically significant according to treatment intensity and days off work due to diabetes, but differences in mental component score (MCS-12) scores failed to reach statistical significance for any of these comparisons.


CONCLUSIONS
Interpretation of the SF-12 summary scores in our study would have overlooked seemingly important differences in health that were picked up by the RAND-12 summary scores.
Johnson
Jeffrey A
JA
Department of Public Health Sciences, University of Alberta, Edmonton, Canada. jeff.johnson@ualberta.ca
Maddigan
Sheri L
SL
D000368:Aged; D000416:Alberta; D003924:Diabetes Mellitus, Type 2 / Q000145:classification / Q000473:pathology / Q000523:psychology / Q000628:therapy; D018450:Disease Progression; D006304:Health Status; D006801:Humans; D008875:Middle Aged; D011788:Quality of Life; D012044:Regression Analysis; D012423:Rural Health; D012720:Severity of Illness Index; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires