TABLE 2—

Odds Ratios (ORs) and 95% Confidence Intervals (CIs) for Prevalence of Knee Pain in Past 12 Months (n = 1115): TDHS, Taipei, Taiwan, 2000

Characteristic	Crude OR (95% CI)	Adjusteda OR (95% CI)
Total driving per day, h
≤ 6	1.00	1.00
6–8	1.70 (0.93, 3.11)	1.99 (1.00, 3.98)
8–10	1.95 (1.12, 3.40)*	2.55 (1.32, 4.94)**
> 10	2.30 (1.35, 3.93)**	3.14 (1.62, 6.08)**
Bending/twisting
Never/rare/seldom	1.00	1.00
Often/sometimes	1.25 (0.92, 1.29)	1.08 (0.75, 1.55)
Very frequently	1.75 (1.09, 2.80)*	1.56 (0.88, 2.75)
Leisure-time physical exertionb
Never/rare/seldom	1.00	1.00
Often/sometimes	1.48 (1.09, 2.01)*	1.35 (0.94, 1.93)
Very frequently	1.78 (1.12, 2.82)*	1.94 (1.12, 3.34)*
Perceived job stress
None	1.00	1.00
Mild	1.58 (1.05, 2.38)*	1.36 (0.85, 2.15)
Moderate to severe	2.49 (1.61, 3.84)**	1.78 (1.06, 2.99)*
Low mental health scorec
No	1.00	1.00
Yes	2.12 (1.57, 2.88)**	1.77 (1.26, 2.50)**
High job dissatisfactiond
No	1.00	1.00
Yes	1.50 (1.07, 2.11)*	1.31 (0.90, 1.91)
Registration type
Affiliated with taxicab company or cooperative practice	1.00	1.00
Individual practice	1.22 (0.91, 1.62)	1.60 (1.09, 2.35)*

^aAdjusted for age, gender, education level, body mass index, marital status, income, smoking, professional seniority in years, days of driving per month, full-time status, frequency of heavy lifting activities, regular exercise, and all the other covariates in the table.

^bThe frequency of bending/twisting and/or heavy lifting when not at work.

^cLow mental health score is defined as standardized mental health score lower than the first quartile as measured by the Taiwanese version of the 36-item Medical Outcomes Study short form (SF-36).

^dHigh job dissatisfaction is defined as those whose job dissatisfaction index are in the highest quartile as measured by the job dissatisfaction subscale in the Job Content Questionnaire.

*P < .05; **P < .01.