Expectant management of ultrasonically diagnosed ovarian dermoid cysts: is it possible to predict outcome?

OBJECTIVE: The aim of this study was to assess the natural history of ultrasonically diagnosed ovarian dermoid cysts in a large group of women who were managed expectantly, and to assess the factors that were associated with failure of expectant management. METHODS: Our database was searched for dermoid cysts diagnosed on ultrasonography by a single expert operator between 2001 and 2007 in this retrospective study. In women who opted for expectant management, demographic data including age, gravidity and parity were recorded. Indications for scan, site of cysts, dimensions and the outcomes of expectant management were also recorded. RESULTS: Two hundred and eighty-nine women were diagnosed with a total of 323 dermoid cysts by a single expert ultrasound operator. 93/289 (32.2%; 95% CI, 26.8-37.6%) women with 105/323 (32.5%; 95% CI, 27.4-37.6%) ovarian dermoid cysts were managed expectantly for longer than 3 months. The mean age at diagnosis was 33.8 (range, 13-79) years and the median duration of follow up was 12.6 (interquartile range, 7.6-29.3) months. The mean growth rate of dermoid cysts during follow up was 1.67 mm/year. There were no demographic or morphological features that could be used to predict the growth rate of dermoid cysts. After a period of expectant management, 24/93 (25.8%; 95% CI, 16.9-34.7%) women had surgical intervention. The risk of surgical intervention was significantly increased in younger women, those of parity > or = 2 and in women with bilateral cysts or larger-diameter cysts, and reduced in women with a past history of ovarian cyst. CONCLUSIONS: The success rate of expectant management of dermoid cysts is high and this approach should be considered as a viable alternative to surgical management.

Improved hospital-level risk adjustment for surveillance of healthcare-associated bloodstream infections: a retrospective cohort study.

BACKGROUND: To allow direct comparison of bloodstream infection (BSI) rates between hospitals for performance measurement, observed rates need to be risk adjusted according to the types of patients cared for by the hospital. However, attribute data on all individual patients are often unavailable and hospital-level risk adjustment needs to be done using indirect indicator variables of patient case mix, such as hospital level. We aimed to identify medical services associated with high or low BSI rates, and to evaluate the services provided by the hospital as indicators that can be used for more objective hospital-level risk adjustment. METHODS: From February 2001-December 2007, 1719 monthly BSI counts were available from 18 hospitals in Queensland, Australia. BSI outcomes were stratified into four groups: overall BSI (OBSI), Staphylococcus aureus BSI (STAPH), intravascular device-related S. aureus BSI (IVD-STAPH) and methicillin-resistant S. aureus BSI (MRSA). Twelve services were considered as candidate risk-adjustment variables. For OBSI, STAPH and IVD-STAPH, we developed generalized estimating equation Poisson regression models that accounted for autocorrelation in longitudinal counts. Due to a lack of autocorrelation, a standard logistic regression model was specified for MRSA. RESULTS: Four risk services were identified for OBSI: AIDS (IRR 2.14, 95% CI 1.20 to 3.82), infectious diseases (IRR 2.72, 95% CI 1.97 to 3.76), oncology (IRR 1.60, 95% CI 1.29 to 1.98) and bone marrow transplants (IRR 1.52, 95% CI 1.14 to 2.03). Four protective services were also found. A similar but smaller group of risk and protective services were found for the other outcomes. Acceptable agreement between observed and fitted values was found for the OBSI and STAPH models but not for the IVD-STAPH and MRSA models. However, the IVD-STAPH and MRSA models successfully discriminated between hospitals with higher and lower BSI rates. CONCLUSION: The high model goodness-of-fit and the higher frequency of OBSI and STAPH outcomes indicated that hospital-specific risk adjustment based on medical services provided would be useful for these outcomes in Queensland. The low frequency of IVD-STAPH and MRSA outcomes indicated that development of a hospital-level risk score was a more valid method of risk adjustment for these outcomes.

Risk stratification for surgical site infections in Australia: evaluation of the US National Nosocomial Infection Surveillance risk index.

This study evaluated the US National Nosocomial Infection Surveillance (NNIS) risk index (RI) in Australia for different surgical site infection (SSI) outcomes (overall, in-hospital, post-discharge, deep-incisional and superficial-incisional infection) and investigated local risk factors for SSI. A SSI surveillance dataset containing 43 611 records for 13 common surgical procedures, conducted in 23 hospitals between February 2001 and June 2005, was used for the analysis. The NNIS RI was evaluated against the observed SSI data using diagnostic test evaluation statistics (sensitivity, specificity, positive predictive value, negative predictive value). Sensitivity was low for all SSI outcomes (ranging from 0.47 to 0.69 and from 0.09 to 0.20 using RI thresholds of 1 and 2 respectively), while specificity varied depending on the RI threshold (0.55 and 0.93 with thresholds of 1 and 2 respectively). Mixed-effects logistic regression models were developed for the five SSI outcomes using a range of available potential risk factors. American Society of Anaesthesiologists (ASA) physical status score >2, duration of surgery, absence of antibiotic prophylaxis and type of surgical procedure were significant risk factors for one or more SSI outcomes, and risk factors varied for different SSI outcomes. The discriminatory ability of the NNIS RI was insufficient for its use as an accurate risk stratification tool for SSI surveillance in Australia and its sensitivity was too low for it to be appropriately used as a prognostic indicator.