Volume 12, Number 5—May 2006
Dispatch
Costs of Surgical Site Infections That Appear after Hospital Discharge
, Kate Halton*†, Merrilyn Curtis*, Shane Doidge*, David Lairson‡, Marylou McLaws§, and Michael Whitby*
Table A1
Effect of surgical site infection (SSI) on cost outcomes controlling for multiple confounding factors,* the results of OLS regression estimated with robust standard errors†‡
| Outcomes | Coeff. on SSI (robust st err) | 95% CI lower:upper | t | p >|t| | R2 | ||
|---|---|---|---|---|---|---|---|
| Costs incurred by healthcare services | |||||||
| No. of contacts with hospital-based services in 4 wk PD | 0.44 (0.26) | –0.07:0.95 | 1.71 | 0.088 | 0.1996 | ||
| Cost of contacts with hospital-based services in 4 wk PD ($) | 15.73 (9.46) | –2.88:34.34 | 1.66 | 0.097 | 0.1971 | ||
| No. of contacts with community-based services in 4 wk PD | 1.36 (0.63)† | 0.13:2.59 | 2.17 | 0.031 | 0.185 | ||
| Cost of contacts with community-based services in 4 wk PD ($) | 47.78 (23.07)† | 2.38:93.18 | 2.07 | 0.039 | 0.1809 | ||
| No. of tests/swabs | –-0.06 (0.35) | –0.75:0.62 | -0.19 | 0.853 | 0.1656 | ||
| Costs of tests/swabs ($) | –3.52 (8.09) | –19.45:12.41 | -0.43 | 0.664 | 0.1668 | ||
| No. of days receiving antimicrobial drugs during 4 wk PD | 6.46 (1.50)† | 3.51:9.41 | 4.31 | >0.001 | 0.1668 | ||
| Costs of antimicrobial drugs | 14.44 (3.76)† | 7.04:21.84 | 3.84 | >0.001 | 0.2994 | ||
| Sum of all costs incurred by healthcare services, excluding costs of readmission ($) | 74.48 (29.48)† | 16.48:132.49 | 2.53 | 0.012 | 0.2056 | ||
| Sum of all costs incurred by healthcare services, including costs of readmission ($) | 123.44 (53.50) | 18.17:228.71 | 2.31 | 0.022 | 0.1985 | ||
| Production losses | |||||||
| Patient production losses during 4 wk PD (min) | 699.83 (1,069.22) | –1,404.18:2,803.84 | 0.65 | 0.513 | 0.3935 | ||
| Monetary valuation of patient production losses ($) | 253.26 (386.93) | –508.15:1,014.67 | 0.65 | 0.513 | 0.3935 | ||
| Informal care givers' production losses during 4 wk PD (min) | 946.42 (579.55) | –193.99:2,086.83 | 1.63 | 0.103 | 0.2787 | ||
| Monetary valuation of informal care giver production losses ($) | 342.53 (209.74) | –70.19:755.26 | 1.63 | 0.103 | 0.2787 | ||
| Private costs incurred by patients | |||||||
| Time patient spent accessing hospital services (min) | 68.57 (74.28) | –77.60:214.73 | 0.92 | 0.357 | 0.1056 | ||
| Time patient spent accessing community-based services (min) | 180.21 (95.38) | –7.46:367.89 | 1.89 | 0.06 | 0.1234 | ||
| Total of out-of-pocket expenditures during 4 wk PD ($) | –3.01 (3.06) | –9.03:3.02 | –0.98 | 0.327 | 0.1672 | ||
| Difference in SF-12 Mental Component Summary (enrollment vs wk 4) | –0.59 (2.32) | –5.16:3.98 | –0.26 | 0.799 | 0.1653 | ||
| Difference in SF-12 Physical Component Summary (enrollment vs wk 4) | 0.49 (2.69) | –4.81:5.79 | 0.18 | 0.855 | 0.1769 | ||
*The coefficient (coeff.) on SSI was estimated after controlling for sex, age, recruiting hospital, length of hospital stay, socioeconomic status, whether patient was in waged employment, salary level, type of surgery (International Classification of Diseases, 10th ed. system), education level, ASA, American Association of Anaesthetists, wound class, duration of surgery, number of coexisting conditions, ethnicity, whether patient was private or public, SF-12, scores at baseline and week 4 postdischarge (PD) (except for the models in which the difference in SF-12 scores is the outcome.
†Statistically significant at the 5% level.
‡OLS, ordinary least squares; robust st err, robust standard error; CI, confidence interval; R2, relative predictive power of model; SF-12, SF-12v2 Health Survey; min, minutes of time.