Exploring the prevalence and construct validity of high-impact chronic pain across chronic low-back pain study samples.

BACKGROUND CONTEXT: The US National Pain Strategy focused attention on high-impact chronic pain and its restrictions. Although many interventions have been studied for chronic low-back pain, results are typically reported for heterogeneous samples. To better understand chronic pain and target interventions to those who most need care, more granular classifications recognizing chronic pain's impact are needed. PURPOSE: To test whether chronic pain impact levels can be identified in chronic low-back pain clinical trial samples, examine the baseline patient mix across studies, and evaluate the construct validity of high-impact chronic pain. STUDY DESIGN/SETTING: Descriptive analyses using 12 large study datasets. PATIENT SAMPLES: Chronic low-back pain patients in nonsurgical, nonpharmacologic trials in the US, Canada, and UK. OUTCOME MEASURES: Preference-based health utilities from the SF-6D and EQ-5D, employment status and absenteeism. METHODS: We used two logistic regression models to predict whether patients had high-impact chronic pain and whether the remainder had low- or moderate-impact chronic pain. We developed these models using two datasets. Models with the best predictive power were used to impute impact levels for six other datasets. Stratified by these estimated chronic pain impact levels, we characterized the case mix of patients at baseline in each dataset, and summarized their health-utilities and work productivity. This study was funded by a National Center for Complementary and Integrative Medicine grant. The authors have no potential conflicts of interest. RESULTS: The logistic models had excellent predictive power to identify those with high-impact chronic pain. Although studies were all of chronic low-back pain patients, the baseline mix of patients varied widely. Across all datasets, utilities, and productivity were similar for those with high-impact chronic pain and worsened as chronic pain impact increased. CONCLUSIONS: There is a need to better categorize chronic pain patients to allow the targeting of optimal interventions for those with each level of chronic pain impact.

Costs and cost-effectiveness of carotid stenting versus endarterectomy for patients at increased surgical risk: results from the SAPPHIRE trial.

OBJECTIVES: To evaluate the cost-effectiveness of carotid stenting vs. carotid endarterectomy using data from the SAPPHIRE trial. BACKGROUND: Carotid stenting with embolic protection has been introduced as an alternative to carotid endarterectomy for prevention of cerebrovascular and cardiovascular events among patients at increased surgical risk. METHODS: Between August 2000 and July 2002, 310 patients with an accepted indication for carotid endarterectomy but at high risk of complications were randomized to and subsequently underwent either carotid stenting (n = 159) or endarterectomy (n = 151). Clinical outcomes, resource use, costs, and quality of life were assessed prospectively for all patients over a 1-year period. Life expectancy, quality-adjusted life expectancy, and health care costs beyond the follow-up period were estimated for patients alive at 1 year, based on observed clinical events during the first year of follow-up. RESULTS: Although initial procedural costs were significantly higher for stenting than for endarterectomy (mean difference: $4,081/patient; 95% CI, $3,849-$4,355), mean post-procedure length of stay was shorter for stenting (1.9 vs. 2.9 days; P < 0.001) with significant associated cost offsets. As a result, initial hospital costs were just $559/patient higher with stenting (95% CI, $3,470 less to $2,289 more). Neither follow-up costs after discharge nor total 1-year costs differed significantly. The incremental cost-effectiveness ratio for stenting compared with endarterectomy was $6,555 per quality-adjusted life year (QALY) gained, with over 98 percent of bootstrap estimates < $50,000/QALY gained. CONCLUSIONS: Although carotid stenting with embolic protection is more costly than carotid endarterectomy, by commonly accepted standards, stenting is an economically attractive alternative to endarterectomy for patients at high surgical risk.

Cost effectiveness of paclitaxel-eluting stents for patients undergoing percutaneous coronary revascularization: results from the TAXUS-IV Trial.

OBJECTIVES: This study sought to compare aggregate medical care costs for patients undergoing percutaneous coronary intervention with paclitaxel-eluting stents (PES) and bare-metal stents (BMS) and to formally evaluate the incremental cost effectiveness of PES for patients undergoing single-vessel percutaneous coronary intervention. BACKGROUND: Although the cost effectiveness of SES has been studied in both clinical trials and decision-analytic models, few data exist on the cost effectiveness of alternative drug-eluting stent (DES) designs. In addition, no clinical trials have specifically examined the cost effectiveness of DES among patients managed without mandatory angiographic follow-up. METHODS: We performed a prospective economic evaluation among 1,314 patients undergoing percutaneous coronary revascularization randomized to either PES (N = 662) or BMS (N = 652) in the TAXUS-IV trial. Clinical outcomes, resource use, and costs (from a societal perspective) were assessed prospectively for all patients over a 1-year follow-up period. Cost effectiveness was defined as the incremental cost per target vessel revascularization (TVR) event avoided and was analyzed separately among cohorts assigned to mandatory angiographic follow-up (n = 732) or clinical follow-up alone (n = 582). RESULTS: The PES reduced TVR by 12.2 events per 100 patients treated, resulting in a 1-year cost difference of 572 dollars per patient with incremental cost-effectiveness ratios of 4,678 dollars per TVR avoided and 47,798 dollars/quality-adjusted life year (QALY) gained. Among patients assigned to clinical follow-up alone, the net 1-year cost difference was 97 dollars per patient with cost-effectiveness ratios of 760 dollars per TVR event avoided and $5,105/QALY gained. CONCLUSIONS: In the TAXUS-IV trial, treatment with PES led to substantial reductions in the need for repeat revascularization while increasing 1-year costs only modestly. The cost-effectiveness ratio for PES in the study population compares reasonably with that for other treatments that reduce coronary restenosis, including alternative drug-eluting stent platforms.