Table 3 Comparison of Self-Report and Administrative Data On Number of Physician Visits and Hospital Nights in the Last 12 Months

Variable Self-report Mean (standard error) Admin Data Mean (standard error) p-value§ Concordance Correlation Coefficient Pearson Correlation Coefficient (Bias Correction Factor Cb)
All respondents (n = 352)
Physician Visits 6.92 (0.37) 11.09 (0.50) <0.0001* 0.58 0.68 (0.85)
Hospital Nights 2.20 (0.62) 1.75 (0.42) 0.09 0.86 0.93 (0.93)
Hospital Nights IBD 1.96 (0.61) 1.46 (0.40) 0.13 0.80 0.88 (0.91)
Respondents with at least one hospital admission by either self-report or administrative data
Hospital Nights n = 63 12.29 (3.16) 9.76 (2.07) 0.09 0.84 0.92 (0.91)
Hospital Nights IBD n = 44 15.70 (4.44) 11.68 (2.76) 0.13 0.75 0.84 (0.89)
1. §Correlated t-test, *statistically significant (p < 0.0001), statistically different from 0 at 0.05 level of significance.
2. Note: Maximum number of physician visits for the self-report data was 57 and for administrative data it was 67. Maximum hospital nights for self-report data was 170 and for administrative data it was 91.