Table 1.
Healthcare costs for ICU patients with S. aureus or P. aeruginosa pneumonia versus controls
| Pneumonia due to S. aureus vs No pneumonia | Pneumonia due to P. aeruginosa vs No pneumonia | ||||||
|---|---|---|---|---|---|---|---|
| No pneumonia, mean (SD) (n = 201,394) | S. aureus pneumonia, mean (SD) (n = 2275) | P. aeruginosa pneumonia, mean (SD) (n = 1007) | Differencea | P valuea | Differenceb | P valueb | |
| (95 % CI) | (95 % CI) | ||||||
| Pre-index costs,c $ (12 months) | |||||||
| Total all-cause costs | 17,379 (38,923) | 24,865 (55,676) | 29,364 (65,771) | 7,487 (6,024, 9,041) | <.001 | 11,985 (9,436, 14,776) | <.001 |
| Inpatient hospitalization costs | 5,985 (25,095) | 10,389 (40,126) | 11,885 (47,091) | 4,405 (3,274, 5,674) | <.001 | 5,900 (4,015, 8,140) | <.001 |
| Index hospitalization costs,c $ | |||||||
| Total costs | 33,851 (51,770) | 146,978 (235,598) | 213,104 (338,552) | 100,216 (94,346, 106,360) | <.001 | 159,361 (146,758, 172,856) | <.001 |
| Post-index costs,c $ (30 days) | |||||||
| Total all-cause costs | 4,732 (18,044) | 8,243 (23,838) | 11,122 (42,503) | 3,773 (3,236, 4,348) | <.001 | 6,327 (5,285, 7,484) | <.001 |
| Inpatient hospitalization costs | 2,610 (17,052) | 4,836 (22,950) | 7,447 (41,852) | 2,710 (2,147, 3,343) | <.001 | 5,139 (3,924, 6,590) | <.001 |
| Post-index costs,c $ (90 days) | |||||||
| Total all-cause costs | 10,575 (27,653) | 17,460 (39,286) | 22,277 (54,113) | 7,250 (6,231, 8,335) | <.001 | 10,842 (9,014, 12,852) | <.001 |
| Inpatient hospitalization costs | 4,913 (23,187) | 9,281 (35,261) | 13,527 (50,214) | 4,731 (3,727, 5,860) | <.001 | 8118 (6,110, 10,513) | <.001 |
| Index hospitalization + post-index costs (30 days),c $ | |||||||
| Total all-cause costs | 38,583 (57,402) | 155,221 (240,527) | 224,226 (346,331) | 101,579 (95,681, 107,742) | <.001 | 162,756 (150,118, 176,254) | <.001 |
| Inpatient hospitalization costs | 36,461 (56,270) | 151,813 (239,022) | 220,552 (344,991) | 102,287 (96,175, 108,687) | <.001 | 163,862 (150,714, 177,947) | <.001 |
CI confidence interval, ICU intensive care unit
aDifferences in means are from gamma regression model (link = log). Statistical comparisons are comparing Cohort 3 (pneumonia due to S. aureus) with Cohort 1 (no pneumonia, reference group); ie, Difference = mean (Cohort 3) − mean (Cohort 1)
bDifferences in means are from gamma regression model (link = log). Statistical comparisons are comparing Cohort 4 (pneumonia due to P. aeruginosa) with Cohort 1 (no pneumonia, reference group); ie, Difference = mean (Cohort 4) − mean (Cohort 1)
cCosts include $0 costs. All costs adjusted for calendar year, reported in 2012 dollars. All costs rounded to nearest dollar
All statistical models were controlled for the following variables: age (continuously), gender, health plan type, geographic region, and DCI comorbidity score. Models of index hospitalization costs and post-index costs were also controlled for the analogous healthcare costs during the 12 month pre-index period. Additional covariates were selected separately for each outcome using a forward selection method. The following additional covariates were considered for inclusion in the models: comorbid conditions (binary for each condition), prior healthcare utilization during the 12 month pre-index period (inpatient stays [0 vs 1+], emergency room visits [0 vs 1+], outpatient and office visits [continuous]), and prior antibiotic use during the 12 month pre-index period (0 vs. 1+)