Measurement characteristics for two health-related quality of life measures in older adults: The SF-36 and the CDC Healthy Days items.
The Short Form Health Survey (SF-36) and the Centers for Disease Control and Prevention (CDC) Healthy Days items are well known measures of health-related quality of life. The validity of the SF-36 for older adults and those with disabilities has been questioned.



Assess the extent to which the SF-36 and the Centers for Disease Control and Prevention (CDC) Healthy Days items measure the same aspects of health; whether the SF-36 and the CDC unhealthy days items are invariant across gender, functional status, or the presence of chronic health conditions of older adults; and whether each of the SF-36's eight subscales is independently associated with the CDC Healthy Days items.



We analyzed data from 66,269 adult Medicare advantage members age 65 and older. We used confirmatory factor analyses and regression modeling to test associations between the CDC Healthy Days items and subscales of the SF-36.



The CDC Healthy Days items were associated with the SF-36 global measures of physical and mental health. The CDC physically unhealthy days item was associated with the SF-36 subscales for bodily pain, physical role limitations, and general health, while the CDC mentally unhealthy days item was associated with the SF-36 subscales for mental health, emotional role limitations, vitality and social functioning. The SF-36 physical functioning subscale was not independently associated with either of the CDC Healthy Days items.



The CDC Healthy Days items measure similar domains as the SF-36 but appear to assess HRQOL without regard to limitations in functioning.
University of Hawai'i at Mānoa, Department of Psychology, 2530 Dole Street, Sakamaki Hall C404, Honolulu, HI 96822-2294, United States. Electronic address: Barile@Hawaii.edu.
John P
JP
Barile
Oregon Health & Science University, Institute on Development & Disability, 3181 S.W. Sam Jackson Park Rd., Portland, OR 97239-3098, United States.
Willi
W
Horner-Johnson
Oregon State University, College of Public Health and Human Sciences, Hallie Ford Center 255, Corvallis, OR 97331, United States.
Gloria
G
Krahn
US Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, 1600 Clifton Road, Atlanta, GA 30329-402, United States.
Matthew
M
Zack
Centers for Medicare and Medicaid Services, Division of Consumer Assessment & Plan Performance, 7500 Security Boulevard, Baltimore, MD 21244, United States.
David
D
Miranda
Centers for Medicare and Medicaid Services, Division of Consumer Assessment & Plan Performance, 7500 Security Boulevard, Baltimore, MD 21244, United States.
Kimberly
K
DeMichele
US Centers for Disease Control and Prevention, National Center for Injury Prevention and Control, 1600 Clifton Road, Atlanta, GA 30329-402, United States.
Derek
D
Ford
US Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities, 1600 Clifton Road, Atlanta, GA 30329-402, United States.
William W
WW
Thompson
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D006233:Persons with Disabilities; D005163:Factor Analysis, Statistical; D005260:Female; D015577:Geriatric Assessment; D006304:Health Status; D006306:Health Surveys / Q000592:standards*; D006801:Humans; D008297:Male; D008603:Mental Health; D010146:Pain; D011788:Quality of Life; D058992:Social Participation
Functional limitations; Health-related quality of life; Healthy Days; Measurement; SF-36