During the study period, 2,607,416 adults had a nonelective hospitalization. Some 1,668,583 hospitalizations were excluded because the patient died during the hospitalization (n= 89,756), the patient was transferred to or from another hospital (n= 97,885), the patient had an invalid Ontario Health Insurance Plan (OHIP) number (n= 5), the patient was discharged from an excluded hospital (n= 19,287), the patient was an outlier (n= 14,614), the patient was missing data (n= 19,246), or the hospitalization was randomly excluded because the patient had other hospitalizations during the study period (n= 1,427,790).
This left 938,833 patients in the study () Most patients had Charlson-Deyo scores of zero. The most common medical diagnostic groups included acute gastroenteritis or gastrointestinal bleeding (8.6% of medical diagnoses), pneumonia (5.1%), and chest pain (5.1%). For surgery, the most common groups included acute fractures (8.8%), appendectomy (7.3%), and laparoscopic cholecystectomy (6.1%). Patients were spread equally through the 5 study years and came from 185 different hospitals. During the entire study, 43.5% of patients were treated in hospital by a physician who had seen them during the 3 months prior to admission. This proportion decreased steadily through the study from 45.6% in 1995 to 41.0% in 1999.
Cohort Description of Baseline, Hospital, and Follow-up Factors and Their Association with 30-Day Risk of Death or Urgent Readmission
Overall, 71,944 (7.7%) patients had an event (). Deaths accounted for 14.6% of events. The risk of death or readmission was highest if patients were older, had been hospitalized in the last 6 months, had a diagnostic group with a high-risk score, or had a medical admission (). The relative risk of death or readmission decreased 3% with each year beyond 1995 (independent hazard ratio, 0.97; 95% confidence interval [CI], 0.96 to 0.98). The univariate analysis showed that the risk of death or readmission increased with each additional visit with all physicians, with community physicians, with specialists, or with hospital physicians ().
Patients had a median of 2 physician visits in the first month after discharge (). Approximately half of these were with hospital physicians. Of the patients, 751,775 (80.1%) had one or more physician visits, 473,814 (50.5%) saw one or more community physicians, 448,035 (47.7%) saw one or more specialists, and 662,029 (70.5%) saw one or more hospital physicians. Patients who saw hospital physicians appeared sicker because they were older, had higher Charlson and diagnostic risk scores, and were more likely to have a medical admission () This was true even when patients with no follow-up visits were excluded ().
Patient Factors Associated with Seeing at Least One Hospital Physician in the First Month After Discharge from Hospital
After controlling for important confounders, patients were significantly less likely to die or be readmitted if they were seen in follow-up by a hospital physician rather than a community physician (hazard ratio, 0.95; 95% CI, 0.95 to 0.96) or specialist (hazard ratio, 0.97; 95% CI, 0.97 to 0.98;) This means that the relative risk of death or readmission decreased by 5% (95% CI, 2% to 4%) when patients followed up with a hospital rather than a community physician. Given a baseline risk of 7.7%, the adjusted risk of 30-day death or nonelective readmission would be 7.3%, 7.0%, and 6.6% for patients who had 1, 2, or 3 visits, respectively, with a hospital rather than a community physician.
Independent Effect of Patient, Hospitalization, and Follow-up Factors on 30-Day Death or Nonelective Readmission
The protective effect of hospital physician follow-up was consistent within important subgroups with some possible exceptions () Compared to community physicians, hospital physician follow-up was significantly protective for all subgroups except patients with previous hospitalizations. Compared to specialists, hospital physician follow-up was significantly protective for all subgroups except those with previous hospitalizations, elderly patients, and those with high-risk diagnoses. The benefit of hospital physician follow-up appeared to decrease as the diagnostic risk score increased. Protection with hospital physician follow-up remained when the analysis was limited to patients whose total number of postdischarge visits did not exceed the 75th percentile. Hospital physician follow-up was more effective for diagnoses thought likely be sensitive to hospital physician follow-up ();Appendix C
, online). Follow-up with a hospital physician versus a community physician was equally beneficial when analysis was limited to patients who were not seen in hospital by community physicians (hazard ratio, 0.95; 95% CI, 0.95 to 0.96). Finally, follow-up with a hospital physician appeared protective (i.e., had a hazard ratio of less than 1.0) for 70 out of the 100 most common diagnoses, which significantly exceeds that expected by chance (P
Subgroup Analysis of the Effect of Hospital Physician Follow-up on 30-Day Death or Nonelective Readmission