Claims-based cardiovascular outcome identification for clinical research: Results from 7 large randomized cardiovascular clinical trials.

BACKGROUND: Medicare insurance claims may provide an efficient means to ascertain follow-up of older participants in clinical research. We sought to determine the accuracy and completeness of claims- versus site-based follow-up with clinical event committee (+CEC) adjudication of cardiovascular outcomes. METHODS: We performed a retrospective study using linked Medicare and Duke Database of Clinical Trials data. Medicare claims were linked to clinical data from 7 randomized cardiovascular clinical trials. Of 52,476 trial participants, linking resulted in 5,839 (of 10,497 linkage-eligible) Medicare-linked trial participants with fee-for-service A and B coverage. Death, myocardial infarction (MI), stroke, and revascularization incidences were compared using Medicare inpatient claims only, site-reported events (+CEC) only, or a combination of the 2. Randomized treatment effects were compared as a function of whether claims-based, site-based (+CEC), or a combined system was used for event detection. RESULTS: Among the 5,839 study participants, the annual event rates were similar between claims- and site-based (+CEC) follow-up: death (overall rate 5.2% vs 5.2%; adjusted κ 0.99), MI (2.2% vs 2.3%; adjusted κ 0.96), stroke (0.7% vs 0.7%; adjusted κ 0.99), and any revascularization (7.4% vs 7.9%; adjusted κ 0.95). Of events detected by claims yet not reported by CEC, a minority were reported by sites but negatively adjudicated by CEC (39% of MIs and 18% of strokes). Differences in individual case concordance led to higher event rates when claims- and site-based (+CEC) systems were combined. Randomized treatment effects were similar among the 3 approaches for each outcome of interest. CONCLUSIONS: Claims- versus site-based (+CEC) follow-up identified similar overall cardiovascular event rates despite meaningful differences in the events detected. Randomized treatment effects were similar using the 2 methods, suggesting claims data could be used to support clinical research leveraging routinely collected data. This approach may lead to more effective evidence generation, synthesis, and appraisal of medical products and inform the strategic approaches toward the National Evaluation System for Health Technology.

Statin intolerance in a referral lipid clinic.

BACKGROUND: Statins effectively prevent atherosclerotic cardiovascular disease, but rates of statin discontinuation after adverse events are high. OBJECTIVE: Describe the range and relative frequencies of adverse events potentially attributable to statins in lipid referral practice and assess statin rechallenge outcomes. METHODS: Retrospective cohort study of 642 patients with statin-associated adverse events evaluated in a referral lipid clinic between January 1, 2004 and January 27, 2011. RESULTS: Patients experiencing adverse events by organ system included 92% with musculoskeletal, 8% central nervous system, 10% liver, 8% gastrointestinal, 5% peripheral nervous system, 5% skin, and 3% other events. Overlap of organ system involvement occurred in 22.5%. At least 1 follow-up visit was made by 557 patients, among whom overall median follow-up was 25 months. Among patients treated with a statin in the clinic, 71% remained on a statin at the last follow-up visit. Patients with hepatic transaminase increases by history were numerically more likely than the overall group to resume or remain on statin treatment, whereas those reporting central nervous system or gastrointestinal symptoms trended lower for statin maintenance. Among patients who experienced an adverse event after statin rechallenge, the majority (64%) were being treated with intermittent, nondaily dosing at the time of the adverse event. CONCLUSION: Although musculoskeletal symptoms are reported by 90% of patients with statin intolerance, symptoms involving other organ systems may be more frequent than previously supposed. Understanding the range of symptoms, time course, and impact on daily activities informs counseling in patient-centered practice, but assessment of causation by statins remains challenging.

Morbidity, mortality, and health care costs for patients undergoing spine surgery following the ACGME resident duty-hour reform: Clinical article.

OBJECT: The Accreditation Council for Graduate Medical Education (ACGME) implemented resident duty-hour restrictions on July 1, 2003, in concern for patient and resident safety. Whereas studies have shown that duty-hour restrictions have increased resident quality of life, there have been mixed results with respect to patient outcomes. In this study, the authors have evaluated the effect of duty-hour restrictions on morbidity, mortality, length of stay (LOS), and charges in patients who underwent spine surgery. METHODS: The Nationwide Inpatient Sample was used to evaluate the effect of duty-hour restrictions on complications, mortality, LOS, and charges by comparing the prereform (2000-2002) and postreform (2005-2008) periods. Outcomes were compared between nonteaching and teaching hospitals using a difference-in-differences (DID) method. Results A total of 693,058 patients were included in the study. The overall complication rate was 8.6%, with patients in the postreform era having a significantly higher rate than those in the pre-duty-hour restriction era (8.7% vs. 8.4%, p < 0.0001). Examination of hospital teaching status revealed complication rates to decrease in nonteaching hospitals (8.2% vs. 7.6%, p < 0.0001) while increasing in teaching institutions (8.6% vs. 9.6%, p < 0.0001) in the duty-hour reform era. The DID analysis to compare the magnitude in change between teaching and nonteaching institutions revealed that teaching institutions to had a significantly greater increase in complications during the postreform era (p = 0.0002). The overall mortality rate was 0.37%, with no significant difference between the pre- and post-duty-hour eras (0.39% vs. 0.36%, p = 0.12). However, the mortality rate significantly decreased in nonteaching hospitals in the postreform era (0.30% vs. 0.23%, p = 0.0008), while remaining the same in teaching institutions (0.46% vs. 0.46%, p = 0.75). The DID analysis to compare the changes in mortality between groups revealed that the difference between the effects approached significance (p = 0.069). The mean LOS for all patients was 4.2 days, with hospital stay decreasing in nonteaching hospitals (3.7 vs. 3.5 days, p < 0.0001) while significantly increasing in teaching institutions (4.7 vs. 4.8 days, p < 0.0001). The DID analysis did not demonstrate the magnitude of change for each group to differ significantly (p = 0.26). Total patient charges were seen to rise significantly in the post-duty-hour reform era, increasing from $40,000 in the prereform era to $69,000 in the postreform era. The DID analysis did not reveal a significant difference between the changes in charges between teaching and nonteaching hospitals (p = 0.55). CONCLUSIONS: The implementation of duty-hour restrictions was associated with an increased risk of postoperative complications for patients undergoing spine surgery. Therefore, contrary to its intended purpose, duty-hour reform may have resulted in worse patient outcomes. Additional studies are needed to evaluate strategies to mitigate these effects and assist in the development of future health care policy.