Raval MV, Cohen ME, Ingraham AM, Dimick JB, Osborne NH, Hamilton BH, Ko CY, Hall BL. Improving American College of Surgeons National Surgical Quality Improvement Program risk adjustment: Incorporation of a novel procedure risk score
ABSTRACT Risk-adjusted evaluation is a key component of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). The purpose of this study was to improve standard ACS NSQIP risk adjustment using a novel procedure risk score.
Current Procedural Terminology codes (CPTs) represented in ACS NSQIP data were assigned to 136 procedure groups. Log odds predicted risk from preliminary logistic regression modeling generated a continuous risk score for each procedure group, used in subsequent modeling. Appropriate subsets of 271,368 patients in the 2008 ACS NSQIP were evaluated using logistic models for overall 30-day morbidity, 30-day mortality, and surgical site infection (SSI). Models were compared when including either work Relative Value Unit (RVU), RVU and the standard ACS NSQIP CPT range variable (CPT range), or RVU and the newly constructed CPT risk score (CPT risk), plus routine ACS NSQIP predictors.
When comparing the CPT risk models with the CPT range models for morbidity in the overall general and vascular surgery dataset, CPT risk models provided better discrimination through higher c statistics at earlier steps (0.81 by step 3 vs 0.81 by step 46), more information through lower Akaike's information criterion (127,139 vs 130,019), and improved calibration through a smaller Hosmer-Lemeshow chi-square statistic (48.76 vs 116.79). Improved model characteristics of CPT risk over CPT range were most apparent for broader patient populations and outcomes. The CPT risk and standard CPT range models were moderately consistent in identification of outliers as well as assignment of hospitals to quality deciles (weighted kappa ≥ 0.870).
Information from focused, clinically meaningful CPT procedure groups improves the risk estimation of ACS NSQIP models.
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- "Our model was similar to, but distinct from, other studies examining SSI risk in patients. The CPT3 Score in our model used an approach similar to that by Raval et al , who used a more clinically robust method to cluster CPT codes into procedural groups. Multiple previous studies have found significant associations between the risk of SSI and factors in our model [including wound class, body mass index, surgical location and urgency, ASA class, the performance of more than one procedure, metastatic cancer, the presence of steroids, and surgical duration] . "
ABSTRACT: Surgical site infections (SSI) are an important cause of peri-surgical morbidity with risks that vary extensively between patients and surgeries. Quantifying SSI risk would help identify candidates most likely to benefit from interventions to decrease the risk of SSI. We randomly divided all surgeries recorded in the National Surgical Quality Improvement Program from 2010 into a derivation and validation population. We used multivariate logistic regression to determine the independent association of patient and surgical covariates with the risk of any SSI (including superficial, deep, and organ space SSI) within 30 days of surgery. To capture factors particular to specific surgeries, we developed a surgical risk score specific to all surgeries having a common first 3 numbers of their CPT code. Derivation (n = 181 894) and validation (n = 181 146) patients were similar for all demographics, past medical history, and surgical factors. Overall SSI risk was 3.9%. The SSI Risk Score (SSIRS) found that risk increased with patient factors (smoking, increased body mass index), certain comorbidities (peripheral vascular disease, metastatic cancer, chronic steroid use, recent sepsis), and operative characteristics (surgical urgency; increased ASA class; longer operation duration; infected wounds; general anaesthesia; performance of more than one procedure; and CPT score). In the validation population, the SSIRS had good discrimination (c-statistic 0.800, 95% CI 0.795-0.805) and calibration. SSIRS can be calculated using patient and surgery information to estimate individual risk of SSI for a broad range of surgery types.PLoS ONE 06/2013; 8(6):e67167. DOI:10.1371/journal.pone.0067167 · 3.23 Impact Factor
Conference Paper: Room temperature diamond coatings for field emittersVacuum Microelectronics Conference, 1997. Technical Digest., 1997 10th International; 09/1997
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ABSTRACT: Many of the environmental management issues which plague decision making processes can be poorly-defined scientifically, or misunderstood in real situations. Even as additional scientific studies clarify issues or impacts, (lack of) communication becomes the governing factor when external stakeholders are involved. In public participation processes, alternative dispute resolution techniques are being continually refined to enhance communication among stakeholders. The science of decision support is also evolving to allow direct participation of stakeholders in planning processes. This paper presents a framework for improving the public consultation process for the case of a popular recreational lake in central Alberta that receives discharge from a coal-fired power plant. Focus is given to the application of a fuzzy decision analysis technique to express subjectivities among stakeholders, and uncertainties in data representation. The fuzzy compromise approach is used to express subjective stakeholder evaluations for the purpose of providing feedback concerning the relative uncertainties in the performance for available alternatives, and for examining the implications of risk averse behaviour among stakeholders. The benefits of incorporating fuzzy sets to express subjectivity and model uncertainty is to clarify the relative performance of alternatives within a risk-based approach, and to identify data gaps which may impact the perception of alternatives or may be sensitive to diverse stakeholder perspectivesSystems, Man, and Cybernetics, 1997. Computational Cybernetics and Simulation., 1997 IEEE International Conference on; 11/1997