Em. Andersen et al., COMPARING THE PERFORMANCE OF HEALTH-STATUS MEASURES FOR HEALTHY OLDERADMITS, Journal of the American Geriatrics Society, 43(9), 1995, pp. 1030-1034
OBJECTIVES: The specific goals of the study were to compare three heal
th status measures among older adults for their correlations with simi
lar scales and to examine whether extreme (positive) health states mig
ht lead to measurement problems. We also report on practical administr
ation and response problems among older adults. DESIGN: Eligible and r
andomly selected health plan enrollees aged 65 and older were sent a b
aseline survey about their health. A random sample of persons who retu
rned this survey was recruited to participate in the comparative study
. Additional questionnaires were completed by mail and telephone inter
views. Measures were repeated at a 1-year follow-up mailing. SETTING:
This study was conducted at Group Health Cooperative (GHC) of Puget So
und, a large prepaid health maintenance organization. PARTICIPANTS: Su
bjects were 200 of the 283 older adults selected (68.2% response). Mea
n age was 72.5 years. MEASUREMENTS: The primary measures were the Sick
ness Impact Profile (SIT), the Quality of Well-being Scale (QWB), and
three scales of the Medical Outcomes Study Short-Form 36 (SF-36). Also
included were a stress scale, the Positive Affect Scale, and the Chro
nic Disease Score (CDS) computed from the automated pharmacy data. RES
ULTS: SIP scores showed a very strong skew toward low (good health) sc
ores with a mean of 3.4% (+/-SD 4.4). The QWB scores ranged from .50 t
o .90 (mean .73+/-.09). For the MOS SF-36 scales, scores of 100 (good
health) were common for both of the physical health scales but not for
general health. Analyses showed the SIP, QWB, and MOS SF-36 scales we
re moderately to strongly correlated with similar measurement scales a
nd with the independent measure of chronic disease and psychosocial he
alth. Scales repeated at 1 year were highly correlated: intraclass cor
relation coefficients between baseline and 1 year ranged from an r = .
51 to .73. CONCLUSIONS: Our results suggest that the SIP is not a usef
ul tool for rating healthy, community-dwelling older adults. Two MOS S
F-36 measures used in this study showed some tendency for ''ceiling''
measurement effects. The QWB demonstrated an acceptable distribution o
f scale scores; however, it is the most complex of the three measures
to administer. Among the broad range of older adults, no one tool appe
ars to apply to every situation.