Table 1.
Relationship Between Diagnosis Frequency and Measures of Physician Encounters and Diagnostic Testing in the United States, 2007
| Measure of Physician Encounters and Diagnostic Testing, per Beneficiary | ||||
|---|---|---|---|---|
| Physician Visits, No. | Different Physicians Seen, No. | Imaging Studies, No. | Laboratory Tests, No. | |
| Correlation with diagnosis frequency, r (95% CI)a | 0.72 (0.66–0.77) | 0.59 (0.51–0.66) | 0.72 (0.66–0.77) | 0.33 (0.23–0.43) |
| Diagnosis frequency, quintile mean (95% CI) | ||||
| Very low (n = 1 019 557) | 11.35 (11.32–11.38) | 3.80 (3.79–3.81) | 3.66 (3.65–3.68) | 10.15 (10.11–10.18) |
| Low (n = 1 038 091) | 12.94 (12.90–12.97) | 4.26 (4.25–4.26) | 4.16 (4.15–4.17) | 11.90 (11.87–11.93) |
| Middle (n = 1 019 701) | 13.20 (13.17–13.24) | 4.21 (4.21–4.22) | 4.36 (4.35–4.37) | 11.96 (11.92–11.99) |
| High (n = 1 039 413) | 14.90 (14.85–14.93) | 4.68 (4.67–4.69) | 4.53 (4.52–4.55) | 12.45 (12.41–12.49) |
| Very high (n = 1 037 115) | 16.19 (16.14–16.24) | 4.95 (4.94–4.96) | 4.69 (4.68–4.71) | 13.93 (13.89–13.97) |
| P value for trend | .002 | .008 | .008 | .01 |
Abbreviations: CI, confidence interval; HRR, hospital referral region.
a
Across 306 hospital referral regions.