Postdischarge Surveillance for Surgical Site Infection: The Continuing Challenge

Patient Self-Assessment of Surgical Site Infection is Inaccurate

BACKGROUND

Availability of surgical site infection (SSI) surveillance rates challenges clinicians, healthcare administrators and leaders and the public. The purpose of this report is to demonstrate the consequences patient self-assessment strategies have on SSI reporting rates.

METHODS

We performed SSI surveillance among patients undergoing general surgery procedures, including telephone follow-up 30 days after surgery. Additionally we undertook a separate validation study in which we compared patient self-assessments of SSI with surgeon assessment. Finally, we performed a meta-analysis of similar validation studies of patient self-assessment strategies.

RESULTS

There were 22/266 in-hospital SSIs diagnosed (8.3%), and additional 16 cases were detected through the 30-day follow-up. In total, the SSI rate was 16.8% (95% CI 10.1-18.5). In the validation survey, we found patient telephone surveillance to have a sensitivity of 66% (95% CI 40-93%) and a specificity of 90% (95% CI 86-94%). The meta-analysis included five additional studies. The overall sensitivity was 83.3% (95% CI 79-88%), and the overall specificity was 97.4% (95% CI 97-98%). Simulation of the meta-analysis results divulged that when the true infection rate is 1%, reported rates would be 4%; a true rate of 50%, the reported rates would be 43%.

CONCLUSION

Patient self-assessment strategies in order to fulfill 30-day SSI surveillance misestimate SSI rates and lead to an erroneous overall appreciation of inter-institutional variation. Self-assessment strategies overestimate SSIs rate of institutions with high-quality performance and underestimate rates of poor performance. We propose such strategies be abandoned. Alternative strategies of patient follow-up strategies should be evaluated in order to provide valid and reliable information regarding institutional performance in preventing patient harm.

Surgical site infections after hip arthroplasty in Norway, 2005-2011: influence of duration and intensity of postdischarge surveillance

BACKGROUND

Most surgical site infections (SSIs) after hip arthroplasty are detected after a patient is discharged from hospital, making postdischarge surveillance (PDS) an important component in surveillance systems. We investigated how long it was necessary to monitor hip arthroplasty patients for SSIs after hospital discharge and if passive PDS through readmissions could replace active PDS by patient questionnaire in detecting SSIs.

METHODS

We used data from the Norwegian surveillance system from 2005-2011, which has active 1-year PDS, to investigate proportions of SSIs found at different time intervals after surgery and whether these SSIs could have been detected through passive PDS by investigating the proportion of patients with SSIs that were readmitted.

RESULTS

We found that 79% of all SSIs and 82% of deep SSIs were detected after hospital discharge. 95% of deep SSIs were detected within 90 days after surgery. 14% of the deep SSIs were detected beyond 30 days after surgery, and all of these patients were readmitted because of their SSI and thus could have been detected by passive PDS.

CONCLUSIONS

Our data suggest that most deep SSIs are detected within 90 days and that passive PDS beyond 30 days after surgery may replace active PDS without reducing sensitivity.

Post-discharge surveillance of wound infections by telephone calls method in a Sudanese Teaching Hospital

Surveillance of wound infections has been shown to be a powerful preventive tool, and feedback to the clinical staff reduces wound infection rates. The main objectives of this study were to identify the applicability of telephone calls as a method of post-discharge wound infection surveillance, and to identify patients and procedures characteristics associated with loss for follow-up after hospital discharge.

MATERIALS AND METHODS

This was a prospective cohort study conducted in Khartoum Teaching Hospital, Sudan. Patients, aged >18 years admitted for elective clean and clean-contaminated surgery during March 1st to 31st October 2010 were recruited. 1-month surveillance of wound infections was conducted with telephone interviews.

RESULTS

Overall 3656 patients were operated on. Of them 1769 (48.4%) were eligible {mean age 37.8+14 years; females, n=1472 (83.3%)}. The performed surgical interventions were 1814. Of these 1277 (70.4%) were clean-contaminated and 537 (29.6%) were clean. Patients who successfully completed the follow-up were 1387 (78.4%), while 368 (20.8%) were lost, and 14 (0.8%) died. The percentage of male patients (85.3%) who successfully completed the follow-up was significantly higher than females (77.8%); (P=0.002). Wound infection was detected in 15 (0.8%) cases during hospital stay and 110 (6.2%) others after hospital discharge.

CONCLUSIONS

The majority of wound infections in the current study appeared in post-discharge period; this emphasis the need for establishment of surveillance program in the hospital. Surveillance of wound infections using telephone calls is applicable in this setting and can be used as an alternative method to clinic-based diagnosis of wound infections.

Prospective assessment of postoperative complications and associated costs following inguinal lymph node dissection (ILND) in melanoma patients

BACKGROUND

We prospectively assessed the incidence, risk factors, and costs associated with wound complications and lymphedema in melanoma patients undergoing inguinal lymph node dissection (ILND).

MATERIALS AND METHODS

A total of 53 melanoma patients were accrued to 2 trials (June 2005 to July 2008) that included prospective evaluations of postoperative complications; 30-day wound complications included infection, seroma, and/or dehiscence. There were 20 patients who underwent limb volume measurement and completed a 19-item lymphedema symptom assessment questionnaire preoperatively and 3 months postoperatively. A multivariate analysis was performed to evaluate potential risk factors for complications. A microcosting analysis was also performed to evaluate the direct costs associated with wound complications.

RESULTS

The 30-day wound complications were noted in 77.4% of patients. A BMI ≥ 30 (n = 28) increased the risk for wound complications (odds ratio [OR] = 11.4, 95% confidence interval [95%CI] 1.6-78.5, P = .01), while advanced nodal disease approached significance (OR = 9.0, 95%CI: 0.79-103.1, P = .08). Other risk factors, including diabetes, smoking, and the addition of a deep pelvic (iliac/obturator) dissection to ILND, were not significant. Of 20 patients, 9 (45%) developed limb volume change (LVC) ≥5% at 3 months, with associated mean symptom scores of 6.1 versus 4.6 for those without LVC. Costs for patients with wound complications were significantly higher than for those without wound complications.

CONCLUSIONS

Postoperative wound complications and early onset lymphedema occur frequently following ILND for melanoma. Obesity is an adverse risk factor for 30-day wound complications that can significantly increase postoperative costs, as is likely the case for advanced disease. Risk reduction practices and novel treatment approaches are needed to reduce postoperative morbidity.