Comparison of responses to SF-36 Health Survey questions with one-week and four-week recall periods.
OBJECTIVE
To compare the measurement properties of acute (one-week recall) and standard (four-week recall) versions of SF-36 Health Survey (SF-36) scale scores.


METHODS
SF-36 data collected from 142 participants (60% female, average age 39) in a clinical trial of an asthma medication: 74 patients randomized to the acute form and 68 to the standard.


METHODS
The SF-36 was self-administered at the time of a clinic visit (before clinical examination) to synchronize with clinical measures of disease severity at three different time points during the clinical trial: -2 weeks (two weeks before randomization to treatment), baseline (week 0 or randomization), and +4 weeks (four weeks after baseline).


RESULTS
The acute form yielded high-quality data; scales conformed to the assumptions of the summated ratings method used to score the standard SF-36; and scales had good distributional properties, were reliable, and had a factor content similar to the standard. The data indicated that while the acute form was more sensitive than the standard to change in health status associated with changes in acute symptoms, acute scale scores may not be comparable to national norms based on the standard, particularly for those scales that assess frequency of health events during a specified time period.


CONCLUSIONS
Results support the use of the acute form in its intended applications; however, further research is required to document the generalizability of greater sensitivity of the acute form to recent changes in health and to explore whether norms based on the standard can be used to interpret the acute scale scores.
Keller
S D
SD
Health Institute, New England Medical Center Hospitals, Boston, MA 02111, USA. san.keller@es.nemc.org
Bayliss
M S
MS
Ware
J E
JE
Hsu
M A
MA
Damiano
A M
AM
Goss
T F
TF
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
D000305:Adrenal Cortex Hormones