Table 2.
Odds ratios from logistic regression models predicting survey response in univariate (Unadjusted) and multivariate models (Adjusted)a
| Variable | Comparison | Unadjusted odds ratiob | Adjusted odds ratioa | Adjusted P value |
|---|---|---|---|---|
| Sex | Female (Reference) | -- | -- | -- |
| Male | 0.757 (0.697–0.823)c | 0.782 (0.718–0.852) | <.001 | |
| Age | 18–29 (Reference) | -- | -- | -- |
| 30–49 | 1.693 (1.457–1.967)c | 1.708 (1.468–1.988) | <.001 | |
| 50–64 | 2.697 (2.334–3.117)c | 2.715 (2.344–3.146) | <.001 | |
| >= 65 | 2.247 (1.930–2.617)c | 3.396 (2.815–4.096) | <.001 | |
| Insurance | Private (Reference) | |||
| Medicaid/Self pay/other | 0.291 (0.238–0.354)c | 0.311 (0.255–0.379) | <.001 | |
| Medicare | 0.775 (0.700–0.857)c | 0.478 (0.413–0.553) | <.001 | |
| Workers comp | 0.578 (0.466–0.718)c | 0.588 (0.472–0.733) | <.001 | |
| Subspecialty | Adult reconstruction (Reference) | -- | -- | |
| Foot and ankle | 0.970 (0.814–1.155) | 1.048 (0.876–1.253) | 0.6086 | |
| Sports | 0.836 (0.706–0.989)c | 0.981 (0.824–1.168) | 0.8282 | |
| Hand | 0.707 (0.593–0.844)c | 0.795 (0.663–0.953) | 0.013 | |
| Spine | 0.686 (0.554–0.851)c | 0.755 (0.607–0.940) | 0.012 | |
| Non-operative | 0.682 (0.585–0.796)c | 0.757 (0.645–0.888) | <.001 | |
| Trauma | 0.504 (0.400–0.635)c | 0.623 (0.492–0.789) | <.001 | |
| Distance | > = 50 miles (Reference) | |||
| <50 miles vs | 1.106 (0.988–1.239) | 1.103 (0.980–1.241) | 0.104 |
aDue to missing data on at least one of the predictor variables, 251 subjects were excluded, leaving 2737 in the responder group and 13791 in the non-responder group
bThese values are given as the odds ratio (OR), with the 95 % confidence-interval (CI) in parentheses, predicting survey response in univariate (unadjusted) and multivariate (adjusted) models, adjusting for gender, age, insurance type, sub-specialty and distance from the clinic
cSignificant at the 0.05 level in the unadjusted analysis