Association between physician continuity throughout observation period and time to death or urgent readmission
| Observation period, mo | Physician continuity within 30 d after discharge | % with event* | Events per 100 patient-years* | Unadjusted HR (95% CI) | Adjusted HR† (95%CI) |
|---|---|---|---|---|---|
| 3 | Follow-up visits, but none with familiar physician | 34.7 | 180 | 1.00 (ref) | 1.00 (ref) |
| < 50% of visits with familiar physician(s) | 17.3 | 142 | 1.00 (0.85–1.16) | 0.92 (0.79–1.08) | |
| 50%–99% of visits with familiar physician(s) | 19.7 | 154 | 1.05 (0.96–1.16) | 0.93 (0.84–1.03) | |
| All visits with familiar physician(s) | 36.1 | 175 | 0.97 (0.89–1.06) | 0.90 (0.82–0.98) | |
| 6 | Follow-up visits, but none with familiar physician | 47.1 | 138 | 1.00 (ref) | 1.00 (ref) |
| < 50% of visits with familiar physician(s) | 26.7 | 101 | 0.96 (0.86–1.08) | 0.89 (0.79–1.01) | |
| 50%–99% of visits with familiar physician(s) | 30.7 | 115 | 1.07 (0.99–1.15) | 0.94 (0.87–1.03) | |
| All visits with familiar physician(s) | 56.2 | 143 | 0.99 (0.92–1.07) | 0.91 (0.85–0.98) | |
| 12 | Follow-up visits, but none with familiar physician | 62.4 | 111 | 1.00 (ref) | 1.00 (ref) |
| < 50% of visits with familiar physician(s) | 40.5 | 78 | 0.96 (0.88–1.05) | 0.90 (0.81–0.99) | |
| 50%–99% of visits with familiar physician(s) | 46.3 | 87 | 1.04 (0.97–1.11) | 0.92 (0.85–0.99) | |
| All visits with familiar physician(s) | 77.6 | 122 | 0.98 (0.92–1.04) | 0.90 (0.84–0.96) |
Note: CI = confidence interval, HR = hazard ratio, ref = referent.
↵* The crude data (% with event and events per 100 person-years) are misleading. For the time-varying groups used in the Cox models, each patient started with a Usual Provider of Continuity Index (UPC) score of 0 (perfect “discontinuity”) or 1 (perfect continuity) after his or her first follow-up visit. Subsequent follow-up time (i.e., the denominator for the person-years column) continued to accrue in the patient’s starting group if his or her UPC score remained 0 or 1; it switched to one of the intermediate UPC groups (change in score to 0.01–0.49 or 0.5–0.99) as soon as the patient saw a different physician; or it was censored if the patient had an outcome event (death or urgent resubmission). Thus, patients who had an event while in the UPC 0 or 1 group were counted in the numerator for that group but without further accrual of follow-up time in the denominator; on the other hand, if patients without an event transition to one of the intermediate groups, their follow-up patient-years would accrue in the denominator for the intermediate groups, thus providing a misleadingly low event rate per 100 patient-years in those groups. This was not an issue in the Cox models used to generate the HRs, because the risk sets were re-evaluated at each timeframe based on the time-varying UPC scores.
↵† See Table 3 for covariates included in the adjusted models at each timeframe. In addition, the models for the above sensitivity analyses included number of outpatient visits after hospital discharge up to each timeframe.