Format

Send to

Choose Destination
PLoS One. 2011 Feb 28;6(2):e17345. doi: 10.1371/journal.pone.0017345.

Differences in self-reported health in the Osteoarthritis Initiative (OAI) and Third National Health and Nutrition Examination Survey (NHANES-III).

Author information

1
Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, Massachusetts, United States of America. wreichmann@partners.org

Abstract

OBJECTIVE:

To assess self-reported health status (SRHS) in two cohorts of participants with radiographic knee osteoarthritis (OA) and examine the extent that differences in SRHS are due to study design.

METHOD:

We used data from the Third National Health and Nutritional Examination Survey (NHANES-III; population-based national survey) and the Osteoarthritis Initiative (OAI; prospective cohort study). Inclusion criteria for this analysis were age 60-79 and presence of radiographic knee OA. SRHS, elicited as a five-item domain (excellent, very good, good, fair, poor), was analyzed by dichotomizing the general health status measure as "fair/poor" versus all other states. We estimated the proportion of participants in fair/poor health from each study. Propensity score methodology was used to adjust for the differences in sampling strategies between the two studies.

RESULTS:

Thirty-four percent (Nā€Š=ā€Š1,608) of OAI and 29% (Nā€Š=ā€Š756) of NHANES-III participants satisfied inclusion criteria. The proportion in fair/poor health was higher in NHANES-III (28%) than in OAI (5%). After adjusting for the propensity score, the proportion in fair/poor health was four times higher in NHANES-III than in OAI.

CONCLUSION:

SRHS was substantially better in OAI than in NHANES-III. Self-selection bias may contribute to overestimation of SRHS in prospective cohort studies such as OAI.

PMID:
21387001
PMCID:
PMC3046148
DOI:
10.1371/journal.pone.0017345
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center