Associations of educational attainment, occupation and community poverty with knee osteoarthritis in the Johnston County (North Carolina) osteoarthritis project.
BACKGROUND
The purpose of this study was to examine data from the Johnston County Osteoarthritis (OA) Project for independent associations of educational attainment, occupation and community poverty with tibiofemoral knee OA.


METHODS
A cross-sectional analysis was conducted on 3,591 individuals (66% Caucasian and 34% African American). Educational attainment (< 12 years or ≥12 years), occupation (non-managerial or not), and census block group household poverty rate (< 12%, 12 to 25%, > 25%) were examined separately and together in logistic models adjusting for covariates of age, gender, race, body mass index (BMI), smoking, knee injury and occupational activity score. Outcomes were presence of radiographic knee OA (rOA), symptomatic knee OA (sxOA), bilateral rOA and bilateral sxOA.


RESULTS
When all three socioeconomic status (SES) variables were analyzed simultaneously, low educational attainment was significantly associated with rOA (odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.20, 1.73), bilateral rOA (OR = 1.43, 95% CI 1.13, 1.81), and sxOA (OR = 1.66, 95% CI 1.34, 2.06), after adjusting for covariates. Independently, living in a community of high household poverty rate was associated with rOA (OR = 1.83, 95% CI 1.43, 2.36), bilateral rOA (OR = 1.56, 95% CI 1.12, 2.16), and sxOA (OR = 1.36, 95% CI 1.00, 1.83). Occupation had no significant independent association beyond educational attainment and community poverty.


CONCLUSIONS
Both educational attainment and community SES were independently associated with knee OA after adjusting for primary risk factors for knee OA.
Thurston Arthritis Research Center, Department of Medicine, 3300 Thurston Building, CB # 7280, University of North Carolina, Chapel Hill, NC 27599-7330, USA. leigh_callahan@med.unc.edu
Leigh F
LF
Callahan
Rebecca J
RJ
Cleveland
Jack
J
Shreffler
Todd A
TA
Schwartz
Britta
B
Schoster
Randy
R
Randolph
Jordan B
JB
Renner
Joanne M
JM
Jordan
D000368:Aged; D003153:Community Health Services / Q000191:economics / Q000639:trends*; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009657:North Carolina / Q000453:epidemiology; D009784:Occupational Diseases / Q000175:diagnosis / Q000191:economics* / Q000453:epidemiology*; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000191:economics* / Q000453:epidemiology*; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000191:economics* / Q000453:epidemiology*; D011203:Poverty / Q000191:economics*; D011859:Radiography; D012307:Risk Factors