Predictors of long-term opioid use and opioid use disorder among construction workers: Analysis of claims data.

BACKGROUND: Construction workers have high rates of work-related musculoskeletal disorders, which lead to frequent opioid use and opioid use disorder (OUD). This paper quantified the incidence of opioid use and OUD among construction workers with and without musculoskeletal disorders. METHODS: We conducted a retrospective study using union health claims from January 2015 to June 2018 from 19,909 construction workers. Claims for diagnoses of chronic musculoskeletal disorders, acute musculoskeletal injuries, musculoskeletal surgery, and other conditions were linked to new opioid prescriptions. We examined the effects of high doses (≥50 morphine mg equivalents per day), large supply (more than 7 days per fill), long-term opioid use (60 or more days supplied within a calendar quarter), and musculoskeletal disorders, on the odds of a future OUD. RESULTS: There were high rates (42.8% per year) of chronic musculoskeletal disorders among workers, of whom 24.1% received new opioid prescriptions and 6.3% received long-term opioid prescriptions per year. Workers receiving opioids for chronic musculoskeletal disorders had the highest odds of future OUD: 4.71 (95% confidence interval 3.09-7.37); workers prescribed long-term opioids in any calendar quarter had a nearly 10-fold odds of developing an OUD. CONCLUSIONS: Among construction workers, opioids initiated for musculoskeletal pain were strongly associated with incident long-term opioid use and OUD. Musculoskeletal pain from physically demanding work is likely one driver of the opioid epidemic in occupations like construction. Prevention of work injuries and alternative pain management are needed for workers at risk for musculoskeletal injuries.

Predicting venous thromboembolism in multiple myeloma: development and validation of the IMPEDE VTE score.

Venous thromboembolism (VTE) is a common cause of morbidity and mortality among patients with multiple myeloma (MM). The International Myeloma Working Group (IMWG) developed guidelines recommending primary thromboprophylaxis, in those identified at high-risk of VTE by the presence of risk factors. The National Comprehensive Cancer Network (NCCN) has adopted these guidelines; however, they lack validation. We sought to develop and validate a risk prediction score for VTE in MM and to evaluate the performance of the current IMWG/NCCN guidelines. Using 4446 patients within the Veterans Administration Central Cancer Registry, we used time-to-event analyses to develop a risk score for VTE in patients with newly diagnosed MM starting chemotherapy. We externally validated the score using the Surveillance, Epidemiology, End Results (SEER)-Medicare database (N = 4256). After identifying independent predictors of VTE, we combined the variables to develop the IMPEDE VTE score (Immunomodulatory agent; Body Mass Index ≥25 kg/m2 ; Pelvic, hip or femur fracture; Erythropoietin stimulating agent; Dexamethasone/Doxorubicin; Asian Ethnicity/Race; VTE history; Tunneled line/central venous catheter; Existing thromboprophylaxis). The score showed satisfactory discrimination in the derivation cohort, c-statistic = 0.66. Risk of VTE significantly increased as score increased (hazard ratio 1.20, P = <.0001). Within the external validation cohort, IMPEDE VTE had a c-statistic of 0.64. For comparison, when evaluating the performance of the IMWG/NCCN guidelines, the c-statistic was 0.55. In summary, the IMPEDE VTE score outperformed the current IMWG/NCCN guidelines and could be considered as the new standard risk stratification for VTE in MM.

Derivation and Validation of a Risk Assessment Model for Immunomodulatory Drug-Associated Thrombosis Among Patients With Multiple Myeloma.

BACKGROUND: Although venous thromboembolism (VTE) is a significant complication for patients with multiple myeloma (MM) receiving immunomodulatory drugs (IMiDs), no validated clinical model predicts VTE in this population. This study aimed to derive and validate a new risk assessment model (RAM) for IMiD-associated VTE. METHODS: Patients with newly diagnosed MM receiving IMiDs were selected from the SEER-Medicare database (n=2,397) to derive a RAM and then data from the Veterans Health Administration database (n=1,251) were used to externally validate the model. A multivariable cause-specific Cox regression model was used for model development. RESULTS: The final RAM, named the "SAVED" score, included 5 clinical variables: prior surgery, Asian race, VTE history, age ≥80 years, and dexamethasone dose. The model stratified approximately 30% of patients in both the derivation and the validation cohorts as high-risk. Hazard ratios (HRs) were 1.85 (P<.01) and 1.98 (P<.01) for high- versus low-risk groups in the derivation and validation cohorts, respectively. In contrast, the method of stratification recommended in the current NCCN Guidelines for Cancer-Associated Venous Thromboembolic Disease had HRs of 1.21 (P=.17) and 1.41 (P=.07) for the corresponding risk groups in the 2 datasets. CONCLUSIONS: The SAVED score outperformed the current NCCN Guidelines in risk-stratification of patients with MM receiving IMiD therapy. This clinical model can help inform providers and patients of VTE risk before IMiD initiation and provides a simplified clinical backbone for further prognostic biomarker development in this population.

Assessment of ICD-10-CM code assignment validity for case finding of outpatient anticoagulant-related bleeding among Medicare beneficiaries.

PURPOSE: To assess performance of International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) code assignments for identifying bleeding events resulting in emergency department visits and hospitalizations among outpatient Medicare beneficiaries prescribed anticoagulants. METHODS: Performance of 206 ICD-10-CM code assignments indicative of bleeding, five anticoagulant adverse effect/poisoning codes, and five coagulopathy codes (according to Medicare Parts A and B claims) as assessed among Medicare fee-for-service beneficiaries prescribed anticoagulants between October 1, 2015 and September 30, 2016 (according to Part D claims). Structured medical record review was the gold standard for validating the presence of anticoagulant-related bleeding. Sensitivity was adjusted to correct for partial verification bias due to sampling design. RESULTS: Based on the study sample of 1166 records (583 cases, 583 controls), 57 of 206 codes yielded the optimal performance for anticoagulant-related bleeding (diagnostic odds ratio, 51; positive predictive value (PPV), 75.7% [95% CI, 72.0%-79.1%]; adjusted sensitivity, 70.0% [95% CI, 63.2%-77.7%]). Codes for intracranial bleeding demonstrated the highest PPV (85.0%) and adjusted sensitivity (91.0%). Bleeding codes in the primary position demonstrated high PPV (86.9%), but low adjusted sensitivity (36.0%). The adjusted sensitivity improved to 69.5% when codes in a secondary position were added. Only one adverse effect/poisoning code was used, appearing in 7.8% of cases and controls (PPV, 71.4% and adjusted sensitivity, 6.8%). CONCLUSIONS: Performance of ICD-10-CM code assignments for bleeding among patients prescribed anticoagulants varied by bleed type and code position. Adverse effect/poisoning codes were not commonly used and would have missed over 90% of anticoagulant-related bleeding cases.

Risk model for estimating the 1-year risk of deferred lesion intervention following deferred revascularization after fractional flow reserve assessment.

AIMS: Although lesions deferred revascularization following fractional flow reserve (FFR) assessment have a low risk of adverse cardiac events, variability in risk for deferred lesion intervention (DLI) has not been previously evaluated. The aim of this study was to develop a prediction model to estimate 1-year risk of DLI for coronary lesions where revascularization was not performed following FFR assessment. METHODS AND RESULTS: A prediction model for DLI was developed from a cohort of 721 patients with 882 coronary lesions where revascularization was deferred based on FFR between 10/2002 and 7/2010. Deferred lesion intervention was defined as any revascularization of a lesion previously deferred following FFR. The final DLI model was developed using stepwise Cox regression and validated using bootstrapping techniques. An algorithm was constructed to predict the 1-year risk of DLI. During a mean (±SD) follow-up period of 4.0 ± 2.3 years, 18% of lesions deferred after FFR underwent DLI; the 1-year incidence of DLI was 5.3%, while the predicted risk of DLI varied from 1 to 40%. The final Cox model included the FFR value, age, current or former smoking, history of coronary artery disease (CAD) or prior percutaneous coronary intervention, multi-vessel CAD, and serum creatinine. The c statistic for the DLI prediction model was 0.66 (95% confidence interval, CI: 0.61-0.70). CONCLUSION: Patients deferred revascularization based on FFR have variation in their risk for DLI. A clinical prediction model consisting of five clinical variables and the FFR value can help predict the risk of DLI in the first year following FFR assessment.

Cost-effectiveness of dabigatran for stroke prophylaxis in atrial fibrillation.

BACKGROUND: Recent studies have investigated alternatives to warfarin for stroke prophylaxis in patients with atrial fibrillation (AF), but whether these alternatives are cost-effective is unknown. METHODS AND RESULTS: On the basis of the results from Randomized Evaluation of Long Term Anticoagulation Therapy (RE-LY) and other trials, we developed a decision-analysis model to compare the cost and quality-adjusted survival of various antithrombotic therapies. We ran our Markov model in a hypothetical cohort of 70-year-old patients with AF using a cost-effectiveness threshold of $50 000/quality-adjusted life-year. We estimated the cost of dabigatran as US $9 a day. For a patient with an average risk of major hemorrhage (≈3%/y), the most cost-effective therapy depended on stroke risk. For patients with the lowest stroke rate (CHADS2 stroke score of 0), only aspirin was cost-effective. For patients with a moderate stroke rate (CHADS2 score of 1 or 2), warfarin was cost-effective unless the risk of hemorrhage was high or quality of international normalized ratio control was poor (time in the therapeutic range <57.1%). For patients with a high stroke risk (CHADS(2) stroke score ≥3), dabigatran 150 mg (twice daily) was cost-effective unless international normalized ratio control was excellent (time in the therapeutic range >72.6%). Neither dabigatran 110 mg nor dual therapy (aspirin and clopidogrel) was cost-effective. CONCLUSIONS: Dabigatran 150 mg (twice daily) was cost-effective in AF populations at high risk of hemorrhage or high risk of stroke unless international normalized ratio control with warfarin was excellent. Warfarin was cost-effective in moderate-risk AF populations unless international normalized ratio control was poor.

Cost-effectiveness of outpatient cardiac monitoring to detect atrial fibrillation after ischemic stroke.

BACKGROUND AND PURPOSE: Extending the duration of continuous electrocardiography after ischemic stroke detects more new cases of atrial fibrillation, which is an important and treatable cause of stroke, but the cost-effectiveness of this approach is unknown. Therefore, we performed a cost-utility analysis of outpatient cardiac monitoring after ischemic stroke. METHODS: Using a Markov model, we determined the lifetime cost and utility of warfarin therapy in a hypothetical cohort of 70-year-old patients with atrial fibrillation, prior stroke, and no contraindication to warfarin therapy. Meta-analysis was used to determine the yield of outpatient cardiac monitoring. RESULTS: Outpatient cardiac monitoring would detect 44 new cases of atrial fibrillation for every 1000 patients monitored. This would result in a gain of 34 quality-adjusted life-years at a net cost of $440,000. Therefore, the cost-utility ratio of outpatient cardiac monitoring would be $13,000 per quality-adjusted life-years gained. Outpatient monitoring remained cost-effective throughout a wide range of model inputs in sensitivity analyses, including changes in the cost and yield of monitoring. CONCLUSIONS: By identifying patients with paroxysmal atrial fibrillation who will benefit from anticoagulation, outpatient cardiac monitoring is cost-effective after ischemic stroke over a wide range of model inputs. The optimal duration and method of monitoring is unknown.

Anemia: an independent predictor of death and hospitalizations among elderly patients with atrial fibrillation.

BACKGROUND: Anemia and atrial fibrillation (AF) are common among the elderly. Anemia is an independent predictor of mortality and morbidity for numerous cardiovascular and noncardiovascular diseases, but the association of anemia with mortality and hospitalizations in patients with AF requires clarification. METHODS: Subjects were 13,067 Medicare beneficiaries hospitalized with AF and included in the National Registry of Atrial Fibrillation II data set. Index hospitalization hematocrit (Hct) was obtained by structured chart abstraction. Cox proportional hazards models quantified the association of Hct with mortality and re-hospitalizations during a median follow-up period of 12 months. RESULTS: The mean age was 79.8 years, 58% were women, and the mean Hct was 39.2%. Hematocrit was significantly (P < .0001) associated with risk of death and of rehospitalization even after adjustment for demographic information, comorbid conditions, and use of cardiovascular medications. As compared to a Hct of 40% to 44.9%, the adjusted hazard ratios for mortality were 1.66 for Hct <25%, 1.50 for 25% to 29.9%, 1.28 for 30% to 34.9%, 1.07 for 35% to 39.9%, 1.03 for 45% to 49.9%, and 1.10 for > or = 50%. The association between anemia and mortality was significant in men and women but stronger in men (P = .006 for interaction). Compared to the category 40% to 44.9%, the risk of rehospitalization was increased to 28% (adjusted hazard ratio 1.28, 95% CI 1.15-1.43) in the Hct category 25% to 29.9%. CONCLUSION: Anemia is an independent predictor of mortality and of hospitalizations in elderly patients with AF. Studies are needed to assess the effect of treatment of anemia on clinical outcomes.

Cost-effectiveness of using pharmacogenetic information in warfarin dosing for patients with nonvalvular atrial fibrillation.

BACKGROUND: Variants in genes involved in warfarin metabolism and sensitivity affect individual warfarin requirements and the risk for bleeding. Testing for these variant alleles might allow more personalized dosing of warfarin during the induction phase. In 2007, the U.S. Food and Drug Administration changed the labeling for warfarin (Coumadin, Bristol-Myers Squibb, Princeton, New Jersey), suggesting that clinicians consider genetic testing before initiating therapy. OBJECTIVE: To examine the cost-effectiveness of genotype-guided dosing versus standard induction of warfarin therapy for patients with nonvalvular atrial fibrillation. DESIGN: Markov state transition decision model. DATA SOURCES: MEDLINE searches and bibliographies from relevant articles of literature published in English. TARGET POPULATION: Outpatients or inpatients requiring initiation of warfarin therapy. The base case was a man age 69 years with newly diagnosed nonvalvular atrial fibrillation and no contraindications to warfarin therapy. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTION: Genotype-guided dosing consisting of genotyping for CYP2C9*2, CYP2C9*3, and/or VKORC1 versus standard warfarin induction. OUTCOME MEASURES: Effectiveness was measured in quality-adjusted life-years (QALYs), and costs were in 2007 U.S. dollars. RESULTS: In the base case, genotype-guided dosing resulted in better outcomes, but at a relatively high cost. Overall, the marginal cost-effectiveness of testing exceeded $170 000 per QALY. On the basis of current data and cost of testing (about $400), there is only a 10% chance that genotype-guided dosing is likely to be cost-effective (that is, <$50 000 per QALY). Sensitivity analyses revealed that for genetic testing to cost less than $50 000 per QALY, it would have to be restricted to patients at high risk for hemorrhage or meet the following optimistic criteria: prevent greater than 32% of major bleeding events, be available within 24 hours, and cost less than $200. LIMITATION: Few published studies describe the effect of genotype-guided dosing on major bleeding events, and although these studies show a trend toward decreased bleeding, the results are not statistically significant. CONCLUSION: Warfarin-related genotyping is unlikely to be cost-effective for typical patients with nonvalvular atrial fibrillation, but may be cost-effective in patients at high risk for hemorrhage who are starting warfarin therapy.

An invasive strategy is associated with decreased mortality in patients 80 years and older with acute myocardial infarction.

The value of invasive therapy in elderly patients with acute myocardial infarction is controversial. The authors performed a retrospective chart review of 140 consecutive patients 80 years and older who were hospitalized with acute myocardial infarction. Hospital outcomes and long-term survival were compared in 79 patients referred for cardiac catheterization during hospitalization with outcomes in 61 patients managed conservatively. Vital status as of December 2003 was determined from the Social Security Death Index. Propensity analysis was used to limit confounding from 13 variables. After a mean follow-up of 333 days, unadjusted mortality was lower in the invasive group (16.5% vs 50.8%; P<.001). The multivariable propensity-adjusted hazard ratio for death was 0.30 (95% confidence interval, 0.11-0.76; P=.01), favoring the invasive group. These data suggest that in patients 80 years and older who are hospitalized with acute myocardial infarction, an invasive strategy confers a significant survival advantage during the first year after hospital discharge.

Use and effectiveness of warfarin in Medicare beneficiaries with atrial fibrillation.

BACKGROUND AND PURPOSE: More than 2 million Americans have atrial fibrillation, and without antithrombotic therapy, their stroke rate is increased 5-fold. In randomized controlled trials, warfarin prevented 65% of ischemic strokes (hazard ratio [HR], 0.35; 95% CI, 0.26 to 0.48) compared with no antithrombotic therapy. However, the effectiveness of warfarin therapy outside of clinical trials is unknown, especially in black and Hispanic populations. Our goal was to quantify use of warfarin therapy, frequency of International Normalized Ratio monitoring, and effectiveness for stroke prophylaxis in Medicare beneficiaries with atrial fibrillation. METHODS: This was a cohort study of Medicare beneficiaries with atrial fibrillation who were hospitalized between March 1998 and April 1999 in all 50 US states. The primary outcome was incident hospitalizations for ischemic stroke based on validated International Classification of Diseases, 9th Revision, Clinical Modification codes. RESULTS: Two thirds of ideal anticoagulation candidates were prescribed warfarin on hospital discharge. In unadjusted analyses, the stroke rates per 100 patient years of warfarin therapy were 5.2 in (non-Hispanic) white Medicare beneficiaries, 10.6 in black beneficiaries, and 12.2 in Hispanic beneficiaries. After adjusting for comorbid conditions, warfarin prescription was more frequent and monitoring more regular in white Medicare beneficiaries than in black or Hispanic beneficiaries (P<0.0001). Warfarin use was associated with 35% fewer ischemic strokes (HR, 0.65; 95% CI, 0.55 to 0.76) compared with no antithrombotic therapy but was less effective in black and Hispanic beneficiaries (P for interaction=0.048). CONCLUSIONS: The use, monitoring, and effectiveness of warfarin therapy are suboptimal in Medicare beneficiaries, especially in black and Hispanic beneficiaries.

Comorbidity indices to predict mortality from Medicare data: results from the national registry of atrial fibrillation.

BACKGROUND: By accounting for level of comorbidity, risk-adjustment models should quantify the risk of death. How accurately comorbidity indices predict risk of death in Medicare beneficiaries with atrial fibrillation is unclear. OBJECTIVES: We sought to quantify how well 3 administrative-data based comorbidity indices (Deyo, Romano, and Elixhauser) predict mortality compared with a chart-review index. DESIGN: We undertook a retrospective cohort study using Medicare claim data (1995-1999) and medical record review. SUBJECTS: We studied Medicare beneficiaries (n = 2728; mean age = 77) with a common cardiac dysrhythmia, atrial fibrillation. MEASURES: The outcome was time to death with the accuracy of the comorbidity indices measured by the c-statistic. RESULTS: Correlation between Deyo and Romano indices was strong, but weak between them and the other indices. Prevalence of many comorbidity conditions varied with different indices. Compared with demographic data alone (c = 0.64), all comorbidity indices predicted death significantly (P < 0.001) better: the c index was 0.76 for Deyo, 0.78 for Romano, 0.76 for Elixhauser, and 0.75 for medical record review. The 95% confidence intervals of the c-statistic for the 4 indices overlapped with one another. Key comorbidity conditions for death included metastatic cancer, neuropsychiatric disease, heart failure, and liver disease. CONCLUSION: The predictive accuracy of 3 administrative-data based indices was similar and comparable with chart-review.

Accuracy of ICD-9-CM codes for identifying cardiovascular and stroke risk factors.

OBJECTIVES: We sought to determine which ICD-9-CM codes in Medicare Part A data identify cardiovascular and stroke risk factors. DESIGN AND PARTICIPANTS: This was a cross-sectional study comparing ICD-9-CM data to structured medical record review from 23,657 Medicare beneficiaries aged 20 to 105 years who had atrial fibrillation. MEASUREMENTS: Quality improvement organizations used standardized abstraction instruments to determine the presence of 9 cardiovascular and stroke risk factors. Using the chart abstractions as the gold standard, we assessed the accuracy of ICD-9-CM codes to identify these risk factors. MAIN RESULTS: ICD-9-CM codes for all risk factors had high specificity (>0.95) and low sensitivity (< or =0.76). The positive predictive values were greater than 0.95 for 5 common, chronic risk factors-coronary artery disease, stroke/transient ischemic attack, heart failure, diabetes, and hypertension. The sixth common risk factor, valvular heart disease, had a positive predictive value of 0.93. For all 6 common risk factors, negative predictive values ranged from 0.52 to 0.91. The rare risk factors-arterial peripheral embolus, intracranial hemorrhage, and deep venous thrombosis-had high negative predictive value (> or =0.98) but moderate positive predictive values (range, 0.54-0.77) in this population. CONCLUSIONS: Using ICD-9-CM codes alone, heart failure, coronary artery disease, diabetes, hypertension, and stroke can be ruled in but not necessarily ruled out. Where feasible, review of additional data (eg, physician notes or imaging studies) should be used to confirm the diagnosis of valvular disease, arterial peripheral embolus, intracranial hemorrhage, and deep venous thrombosis.

Costs and effectiveness of ximelagatran for stroke prophylaxis in chronic atrial fibrillation.

CONTEXT: Recent trials have found that ximelagatran and warfarin are equally effective in stroke prevention for patients with atrial fibrillation. Because ximelagatran can be taken in a fixed, oral dose without international normalized ratio monitoring and may have a lower risk of hemorrhage, it might improve quality-adjusted survival compared with dose-adjusted warfarin. OBJECTIVE: To compare quality-adjusted survival and cost among 3 alternative therapies for patients with chronic atrial fibrillation: ximelagatran, warfarin, and aspirin. DESIGN: Semi-Markov decision model. PATIENTS: Hypothetical cohort of 70-year-old patients with chronic atrial fibrillation, varying risk of stroke, and no contraindications to anticoagulation therapy. MAIN OUTCOME MEASURES: Quality-adjusted life-years (QALYs) and costs in US dollars. RESULTS: For patients with atrial fibrillation but no additional risk factors for stroke, both ximelagatran and warfarin cost more than 50,000 dollars per QALY compared with aspirin. For patients with additional stroke risk factors and low hemorrhage risk, ximelagatran modestly increased quality-adjusted survival (0.12 QALY) at a substantial cost (116,000 dollars per QALY) compared with warfarin. For ximelagatran to cost less than 50,000 dollars per QALY it would have to cost less than 1100 dollars per year or be prescribed to patients who have an elevated risk of intracranial hemorrhage (>1.0% per year of warfarin) or a low quality of life with warfarin therapy. CONCLUSION: Assuming equal effectiveness in stroke prevention and decreased hemorrhage risk, ximelagatran is not likely to be cost-effective in patients with atrial fibrillation unless they have a high risk of intracranial hemorrhage or a low quality of life with warfarin.

Cost-effectiveness of extending Medicare coverage of immunosuppressive medications to the life of a kidney transplant.

Unless they maintain Medicare status through disability or age, kidney transplant recipients lose their Medicare coverage of immunosuppression 3 years after transplantation. A significant transplant survival advantage has previously been demonstrated by the extension of Medicare immunosuppressive medication coverage from 1 year to 3 years, which occurred between 1993 and 1995. The United States Renal Data System (USRDS) was analyzed for recipients of kidney transplants from 1995 to 1999. Using a Markov model, we estimated survival and costs of the current system of 3-year coverage compared with lifetime immunosuppression coverage. Results were calculated from the perspectives of society and Medicare. Extension of immunosuppression coverage produced an expected improvement from 38.6% to 47.6% in graft survival and from 55.4% to 61.8% in patient survival. The annualized expected savings to society from lifetime coverage was $136 million assuming current rates of transplantation. Medicare would break-even compared with current coverage if the fraction of patients using extended coverage was <32%. The extension would be cost-effective to Medicare if this fraction was <91%. Extended Medicare immunosuppression coverage to the life of a kidney transplant should result in better transplant and economic outcomes, and should be considered by policy makers.

The management of anticoagulants in the periendoscopic period for patients with atrial fibrillation: a decision analysis.

PURPOSE: The management of patients who undergo endoscopy while being treated with warfarin is challenging. We used decision analysis to determine the preferred strategy to manage anticoagulants in the periendoscopic period. METHODS: We designed a Markov model to estimate costs and quality-adjusted survival during a 10-year period in patients with nonvalvular atrial fibrillation undergoing screening colonoscopy. We compared six alternatives to the continue-warfarin strategy, which was to perform colonoscopy while the patient was taking full-dose warfarin. The hold-warfarin strategy was to stop warfarin 5 days before the colonoscopy. The repeat endoscopy strategy was to continue warfarin for a diagnostic colonoscopy, followed by a repeat procedure after cessation of warfarin if polypectomy was required. The dose-reduction strategy was to reduce the warfarin dose before colonoscopy. The low molecular weight heparin strategy was to administer subcutaneous low molecular weight heparin for 2 days before and 2 days after colonoscopy. The unfractionated heparin strategy was to administer intravenous unfractionated heparin for 2 days before and 2 days after the procedure. The vitamin K strategy was to hold warfarin for 4 days and to administer vitamin K if the international normalized ratio (INR) exceeded 2.0 the day before the procedure, or low molecular weight heparin if the INR was less than 1.5. RESULTS: For screening colonoscopy, assuming that polyps would be removed in 35% of examinations, the hold-warfarin and dose-reduction arms were both cost-effective strategies. The hold-warfarin arm was most cost-effective if the likelihood of polypectomy exceeded 60%, or if there was a low risk of stroke despite atrial fibrillation. The continue-warfarin strategy was preferred if the probability of polypectomy was 1% or less. CONCLUSION: Temporary warfarin cessation or halving the warfarin dose for several days before endoscopy was the preferred strategy for most patients. Periendoscopic heparin therapy was not cost-effective for patients with nonvalvular atrial fibrillation.

Cost-savings analysis of using a portable coagulometer for monitoring homebound elderly patients taking warfarin.

The authors present a prospective cost-savings analysis to determine how the use of portable coagulometers in the home health setting affects medical expenditure. Thirty-five elderly patients (mean age 67 years) receiving cardiac home health care and long-term oral anticoagulation were evaluated with paired measurements of the international normalized ratio by both a traditional, laboratory-based prothrombin time and a point-of-care coagulometer (CoaguChek, Roche Diagnostics, Basel, Switzerland). Costs for materials, procedures, transportation, and labor were summed for both methods, and it was found that cost of international normalized ratio determination by the portable coagulometer was significantly less than the traditional method ($6.85 vs. $17.30; p<0.001). The authors conclude that by saving on the costs of transporting and processing traditional international normalized ratio specimens, use of point-of-care coagulometers by home health nurses could reduce medical expenditure. The cost savings and potential improvement in quality of care argue for equipping home health nurses with portable coagulometers.

Warfarin dose reduction vs watchful waiting for mild elevations in the international normalized ratio.

BACKGROUND: Whether clinicians should decrease the warfarin dose in response to a mild, asymptomatic elevation in the international normalized ratio (INR) is unknown. OBJECTIVES: The study objectives were as follows: (1) to evaluate the safety of an anticoagulation service (ACS) policy advocating that the warfarin dose not be changed for isolated, asymptomatic INRs of < or = 3.4; (2) to compare the dosing strategies of an ACS and primary care providers (PCPs); and (3) to quantify the relationship between reduction of the warfarin dose and the subsequent fall in the INR. DESIGN AND SETTING: Randomized controlled study of health maintenance organization outpatients who were receiving warfarin. PATIENTS: We identified 231 patients with a target INR of 2.5 and an isolated, asymptomatic INR between 3.2 and 3.4. Our ACS monitored 103 of the patients; PCPs monitored the remaining 128 patients. MEASUREMENTS: From all 231 patients, we obtained INRs and warfarin dosing history. From the 103 ACS enrollees, we also recorded adverse events. RESULTS: One ACS patient had epistaxis in the 30 days after the elevated INR. Twenty-three percent of ACS enrollees and 47% of PCP patients reduced their warfarin dose (p < 0.001). The median follow-up INRs were similar in both cohorts: 2.7 in the ACS enrollees and 2.6 in the PCP patients. However, in a subgroup analysis of 190 patients who presented with an INR of 3.2 or 3.3, ACS enrollees were more likely to have a follow-up INR in the range of 2 to 3 (p = 0.03). The median follow-up INR was 2.7 in 148 patients who maintained their warfarin dose, 2.5 in 77 patients who decreased their dose by 1 to 20%, and 1.7 in 6 patients who decreased their dose by 21 to 43% (p < 0.001). CONCLUSIONS: These findings support maintaining the same warfarin dose in asymptomatic patients with an INR of < or = 3.3, and reducing the dose for patients who have a greater INR or an increased risk of hemorrhage. Warfarin dose reductions > 20% should be avoided for mildly elevated INRs.