Table 3:

Health services outcomes for all procedures combined, by day of the week of surgery

OutcomeMonday (n = 77 082)Tuesday (n = 95 654)Wednesday (n = 86 853)Thursday (n = 78 171)Friday (n = 65 139)p value*
30-day readmission
 No. (%) of events6100 (7.9)7574 (7.9)7057 (8.1)6338 (8.1)5169 (7.9)
 Unadjusted OR (95% CI)1.00 (ref)1.00 (0.97–1.04)1.03 (0.99–1.07)1.03 (0.99–1.07)1.00 (0.96–1.04)0.3
 Adjusted OR (95% CI)1.00 (ref)1.05 (1.01–1.09)1.06 (1.01–1.10)1.04 (1.00–1.08)1.02 (0.98–1.06)0.06
30-day reoperation
 No. (%) of events3219 (4.2)3943 (4.1)3870 (4.5)3447 (4.4)2743 (4.2)
 Unadjusted OR (95% CI)1.00 (ref)0.99 (0.94–1.03)1.07 (1.02–1.12)1.06 (1.01–1.11)1.01 (0.96–1.06)0.001
 Adjusted OR (95% CI)1.00 (ref)0.97 (0.92–1.03)1.03 (0.97–1.09)1.01 (0.95–1.07)0.96 (0.90–1.02)0.2
ICU admission
 No. (%) of events19 193 (24.9)23 329 (24.4)22 392 (25.8)18 579 (23.8)15 358 (23.6)
 Unadjusted OR (95% CI)1.00 (ref)0.97 (0.95–0.99)1.05 (1.02–1.07)0.94 (0.92–0.96)0.93 (0.91–0.95)< 0.001
 Adjusted OR (95% CI)1.00 (ref)1.05 (1.00–1.10)1.02 (0.98–1.07)1.09 (1.03–1.15)1.07 (1.02–1.12)0.03
Length of stay, d
 Median (IQR)5 (4–8)6 (4–8)6 (5–8)6 (5–8)6 (5–8)< 0.001
 Mean ± SD7.5 ± 9.17.6 ± 9.27.7 ± 8.87.8 ± 9.07.9 ± 8.8< 0.001
Weekend stay, no. (%)37 828 (49.1)68 699 (71.8)79 144 (91.1)76 897 (98.4)65 076 (99.9)< 0.001
  • Note: CI = confidence interval, ICU = intensive care unit, IQR = interquartile range, OR = odds ratio, ref = reference category, SD = standard deviation.

  • * p values represent an overall test of significance, not a comparison of individual odds ratios.

  • Adjusted for patient age, sex, comorbidity (RUB), income quintile, hospital teaching status, procedure, year of the procedure, surgeon years of experience, and surgeon procedure-specific annual volume.

  • Weekend stay represents the number (%) of patients whose hospital stay included Saturday, Sunday or both.