Improved coding of postoperative deep vein thrombosis and pulmonary embolism in administrative data (AHRQ Patient Safety Indicator 12) after introduction of new ICD-9-CM diagnosis codes.

BACKGROUND: Symptomatic venous thromboembolism is a common postoperative complication. The Agency for Healthcare Research and Quality (AHRQ) has developed a Patient Safety Indicator 12 to assist hospitals, payers, and other stakeholders to identify patients who experienced this complication. OBJECTIVES: To determine whether newly created and recently redefined ICD-9-CM codes improved the criterion validity of Patient Safety Indicator 12, based on new samples of records dated after October 2009. RESEARCH DESIGN, SUBJECTS, MEASURES: Two sources of data were used: (1) UHC retrospective case-control study of risk factors for acute symptomatic venous thromboembolism occurring within 90 days after total knee arthroplasty in teaching hospitals; (2) chart abstraction data by volunteer hospitals participating in the Validation Pilot Project of the AHRQ. RESULTS: In the UHC sample, the positive predictive value (PPV) was 99% (125/126) and the negative predictive value was 99.4% (460/463). In the AHRQ sample, the overall PPV was 81% (126/156). CONCLUSIONS: The PPV based on both samples shows substantial improvement compared with the previously reported PPVs of 43%-48%, suggesting that changes in ICD-9-CM code architecture and better coding guidance can improve the usefulness of coded data.

Variation in academic medical centers' coding practices for postoperative respiratory complications: implications for the AHRQ postoperative respiratory failure Patient Safety Indicator.

BACKGROUND: The Agency for Healthcare Research and Quality Patient Safety Indicator (PSI) 11 uses International Classification of Disease, 9th Clinical Modification diagnosis code 518.81 ("Acute respiratory failure")-but not the closely related alternative, 518.5 ("Pulmonary insufficiency after trauma and surgery")-to detect cases of postoperative respiratory failure. We sought to determine whether hospitals vary in the use of 518.81 versus 518.5 and whether such variation correlates with coder beliefs. STUDY DESIGN: We conducted a cross-sectional analysis of administrative data from July 2009 through June 2010 for UHC (formerly University HealthSystem Consortium)-affiliated centers to assess the use of diagnosis codes 518.81 and 518.5 in PSI 11-eligible cases. We also surveyed coders at these centers to evaluate whether variation in the use of 518.81 versus 518.5 might be linked to coder beliefs. We asked survey respondents which diagnosis they would use for 2 ambiguous cases of postoperative pulmonary complications and how much they agreed with 6 statements about the coding process. RESULTS: UHC-affiliated centers demonstrated wide variation in the use of 518.81 and 518.5, ranging from 0 to 26 cases and 0 to 56 cases/1000 PSI 11-eligible hospitalizations, respectively. Of 56 survey respondents, 64% chose 518.81 and 30% chose 518.5 for a clinical scenario involving postoperative respiratory failure, but these responses were not associated with actual coding of 518.81 or 518.5 at the center level. Sixty-two percent of respondents agreed that they are constrained by the words that physicians use. Their self-reported likelihood of querying physicians to clarify the diagnosis was significantly associated with coding of 518.5 at the center level. CONCLUSIONS: The extent to which diagnosis code 518.81 is used relative to 518.5 varies considerably across centers, based on local coding practice, the specific wording of physician documentation, and coder-physician communication. To standardize the coding of postoperative respiratory failure, the 518.81 and 518.5 codes have recently been revised to make the available options clearer and mutually exclusive, which may improve the capacity of PSI 11 to discriminate true differences in quality of care.

Mechanical and suboptimal pharmacologic prophylaxis and delayed mobilization but not morbid obesity are associated with venous thromboembolism after total knee arthroplasty: a case-control study.

BACKGROUND: The FDA-approved dose of low-molecular-weight heparin (LMWH) may not provide adequate thromboprophylaxis in morbidly obese patients after total knee arthroplasty (TKA). Suboptimal dosing, delayed initiation, and overreliance on mechanical methods may also limit the effectiveness of thromboprophylaxis. OBJECTIVE: We explored the associations between the type of thromboprophylaxis, obesity, time of mobilization, and undergoing bilateral TKA on development of symptomatic venous thromboembolism (VTE) after TKA. DESIGN/SETTING/PATIENTS: This was a case-control study of patients undergoing TKA in 15 teaching hospitals between October 2008 and March 2010. Cases were screened using the Agency for Healthcare Research and Quality's Patient Safety Indicator 12 and had objectively documented acute VTE within 9 days of surgery; controls were randomly selected from the same hospital. Multivariable logistic regression was used to analyze risk factors for postoperative VTE, adjusted for age and gender. RESULTS: Among 130 cases with and 463 controls without acute VTE, body mass index (BMI) ranged from 17 to 61 (median = 34). Thromboprophylaxis was LMWH in 284 (48%), warfarin in 189 (32%), both in 55 (10%), and mechanical prophylaxis alone in 120 (20%). Overall, 77% ambulated on day 1 or 2 after surgery. Factors significantly associated with VTE were bilateral simultaneous TKA (odds ratio [OR] = 4.2; 95% confidence interval [CI]: 1.9-9.1), receipt of FDA-approved pharmacological prophylaxis (OR = 0.5; 95% CI: 0.3-0.8), and ambulation by postoperative day 2 (OR = 0.3; 95% CI: 0.1-0.9). Obesity was neither a significant confounder nor a modifier of these effects. CONCLUSIONS: Severe obesity was not a significant independent predictor for VTE and did not modify the beneficial effect of FDA-approved pharmacological thromboprophylaxis. Bilateral TKA and failure to ambulate by the second day after surgery were significant risk factors.

Hospital discharge documentation and risk of rehospitalisation.

BACKGROUND Avoidable hospital readmission is a focus of quality improvement efforts. The effectiveness of individual elements of the standard discharge process in reducing rehospitalisation is unknown. METHODS The authors conducted a case-control study of 1039 patients experiencing rehospitalisation within 30 days of discharge and 981 non-rehospitalised patients matched on admission diagnosis, discharge disposition, and severity of illness. In separate models for each discharge process component, the authors measured the relationship between readmission and discharge summary completion, contents of discharge summary, completion of discharge instructions, contents of discharge instructions, presence of caregiver for discharge instruction, completion of medication reconciliation, and arrangement of ambulatory follow-up prior to discharge. RESULTS Adjusting for patient and hospital characteristics, including severity of illness and discharge disposition, the study failed to find an association between readmission and most components of the discharge process. There was no association between readmission and medication reconciliation, transmission of discharge summary to an outpatient physician, or documentation of any specific aspect of discharge instruction. Associations were found between readmission and discharge with followup arranged (adjusted odds ratio (OR) 1.21; 95% CI 1.05 to 1.37) and increasing number of medicines (adjusted OR 1.02; 95% CI 1.01 to 1.04). CONCLUSIONS Documentation of discharge process components in the medical record may not reflect actual discharge process activities. Alternatively, mandated discharge processes are ineffective in preventing readmission. The observed absence of an association between discharge documentation and readmission indicates that discharge quality improvement initiatives should target metrics of discharge process quality beyond improving rates of documentation.