Table 4.
Multilevel logistic regression with random effects for the main treating physician: Model 1) received any non-recommended imaging service determined to be for surveillance purposes (computed tomography scan, magnetic resonance imaging, ultrasound, bone scan, positron emission tomography scan); Model 2) received any post-treatment mammogram; and Model 3) received any non-recommended biomarker test: carcinoembryonic antigen (CEA), cancer antigen (CA) 15-3, CA 27.29, and CA 125 tests. The group variable is the main treating physician. N=258
| Model 1: Received any non-recommended imaging service for surveillance | ||||
|---|---|---|---|---|
| Variable | Odds ratio | Standard error | p-value | 95% confidence interval |
| Mastectomy | 1.97 | 0.89 | 0.13 | [0.81, 4.76] |
| Radiation | 1.77 | 0.76 | 0.19 | [0.76, 4.12] |
| Chemotherapy | 1.34 | 0.34 | 0.24 | [0.82, 2.18] |
| Stage 2/3A | 2.70 | 1.04 | 0.01 | [1.27, 5.74] |
| Age at diagnosis | 0.97 | 0.02 | 0.05 | [0.93, 0.99] |
| PPO insurance | 0.55 | 0.28 | 0.23 | [0.20, 1.48] |
| Medicare | 0.79 | 0.37 | 0.61 | [0.31, 1.97] |
| Years since diagnosis | 1.23 | 0.11 | 0.02 | [1.03, 1.46] |
| Sigma_u | 0.89 | 0.29 | [0.47, 1.68] | |
| Intraclass correlation (rho)* | 0.19 | 0.10 | [0.06, 0.46] | |
| Likelihood ratio test: rho=0 chibar2(01)=17.33 Prob >=chibar2 = 0.000 | ||||
| Model 2: Received any post-treatment mammogram | ||||
| Variable | Odds ratio | Standard error | p-value | 95% confidence interval |
| Mastectomy | 0.88 | 0.36 | 0.76 | [0.39, 1.97] |
| Radiation | 1.98 | 0.78 | 0.08 | [0.92, 4.30] |
| Chemotherapy | 0.93 | 0.22 | 0.77 | [0.59, 1.48] |
| Stage 2/3A | 1.17 | 0.46 | 0.69 | [0.54, 2.52] |
| Age at diagnosis | 0.94 | 0.02 | 0.001 | [0.91,0.98] |
| PPO insurance | 1.21 | 0.59 | 0.70 | [0.46,3.16] |
| Medicare | 8.99 | 4.82 | 0.000 | [3.14, 25.72] |
| Years since diagnosis | 1.06 | 0.09 | 0.51 | [0.89, 1.26] |
| Sigma_u | 0.97 | 0.36 | [0.47, 2.01] | |
| Intraclass correlation (rho)* | 0.22 | 0.13 | [0.06, 0.56] | |
| Likelihood ratio test: rho=0 chibar2(01)=10.18 Prob >=chibar2 = 0.001 | ||||
| Model 3: Received any non-recommended biomarker test | ||||
| Variable | Odds ratio | Standard error | p-value | 95% confidence interval |
| Mastectomy | 1.27 | 0.79 | 0.70 | [0.38, 4.28] |
| Radiation | 0.94 | 0.54 | 0.91 | [0.30, 2.93] |
| Chemotherapy | 1.59 | 0.50 | 0.14 | [0.86, 2.93] |
| Stage 2/3A | 4.24 | 2.93 | 0.04 | [1.10, 16.43] |
| Age at diagnosis | 1.02 | 0.03 | 0.43 | [0.97, 1.07] |
| PPO insurance | 1.17 | 0.78 | 0.82 | [0.31, 4.35] |
| Medicare | 0.99 | 0.67 | 0.99 | [0.26, 3.75] |
| Years since diagnosis | 1.42 | 0.18 | 0.006 | [1.11, 1.83] |
| Sigma_u | 2.04 | 0.59 | [1.16, 3.59] | |
| Intraclass correlation (rho)* | 0.56 | 0.14 | [0.29, 0.80] | |
| Likelihood ratio test: rho=0 | chibar2(01)=33.11 Prob >=chibar2 = 0.000 | |||
Reference groups: Lumpectomy, health maintenance organization (HMO) insurance, stage 0/1 disease
The intraclass correlation (rho) is the amount of variance in the outcome accounted for by the group variable, main treating physician
Abbreviations: PPO: Preferred provider organization