First, a stratified random sample of 1,880 Quebec physicians was selected from the master physician file of the Quebec Health Insurance Program (RAMQ).
Although the majority of index strokes in this study were first recorded in the physician file, this does not imply that most of these patients were not hospitalized.
On the other hand, our own gender results are consistent with another large survey that used the American Medical Association physician file (McFarlane et al, 2007), which suggests that our source of respondents may have had a role.
We used work by Taylor et al. and Ray et al. that applied complex algorithms to Medicare data (specifically, inpatient, ED, outpatient, and physician files) to examine incidence of fractures (Ray et al. 1992; Taylor et al. 2011).
Conditions were determined to be present based on Medicare claims in inpatient, outpatient, or physician files.
Pathology reports, patient diaries, and information from physician files were used, where possible, to confirm information.
The 100% Physician/Supplier (physician) files were a subset of the National Claims History files, and were referred to as the NCH files.
Diagnostic coding for comorbidities was made only if the comorbidity condition was included in Medicare inpatient files or if the condition had been coded at least twice at least 30 days apart in either the outpatient or physician files.
From Medicare inpatient, outpatient, and physician files we identified those patients who experienced postoperative complications (extrapulmonary infections, cardiovascular complications, thromboembolic events, respiratory complications, reoperations, and transfusions) within 30 days of surgery.
Typically, physicians file claims to a regional claims processing clearinghouse.
Not exactly Internet, but still a growing market, says Dalton, who thinks that only about one-third of independent physicians file their claims for insurance companies electronically, while the rest of them do it manually.
