Cost-Effectiveness of AF Screening With 2-Week Patch Monitors: The mSToPS Study

Abstract

Background: The mSToPS study (mHealth Screening to Prevent Strokes) reported screening older Americans at risk for atrial fibrillation (AF) and stroke using 2-week patch monitors was associated with increased rates of AF diagnosis and anticoagulant prescription within 1 year and improved clinical outcomes at 3 years relative to matched controls. Cost-effectiveness of this AF screening approach has not been explored.

Methods: We conducted a US-based health economic analysis of AF screening using patient-level data from mSToPS. Clinical outcomes, resource use, and costs were obtained through 3 years using claims data. Individual costs, survival, and quality-adjusted life years (QALYs) were projected over a lifetime horizon using regression modeling, US life tables, and external data where needed. Adjustment between groups was performed using propensity score bin bootstrapping.

Results: Screening participants (mean age, 74 years, 41% female, median CHA₂DS₂-VASC score 3) wore on average 1.7 two-week monitors at a mean cost of $614/person. Over 3 years, outpatient visits were more frequent for monitored than unmonitored individuals (difference 190 per 100 patient-years [95% CI, 82-298]), but emergency department visits (-8.3 [95% CI, -12.6 to -4.1]) and hospitalizations (-15.2 [CI, -22 to -8.6]) were less frequent. Total adjusted 3-year costs were slightly higher (mean difference, $1551 [95% CI, -$1047 to $4038]) in the monitoring group. In patient-level projections, the monitoring group had slightly greater quality-adjusted survival (8.81 versus 8.71 QALYs, difference, 0.09 [95% CI, -0.05 to 0.24]) and slightly higher lifetime costs, resulting in an incremental cost-effectiveness ratio of $36 100/QALY gained. With bootstrap resampling, the incremental cost-effectiveness ratio for monitoring was <$50 000/QALY in 64% of study replicates, and <$150 000/QALY in 91%.

Conclusions: Using lifetime projections derived from the mSToPS study, we found that AF screening using 2-week patch monitors in older Americans was associated with high economic value. Confirmation of these uncertain findings in a randomized trial is warranted.

Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02506244.

Keywords: atrial fibrillation; cost effectiveness analysis; electrocardiography, ambulatory; oral anticoagulants.

Figure 1.

Analytic overview. For both study groups, clinical outcomes, resource utilization, and costs were tracked through 3 y using insurance claims data. Thereafter, patient-level costs and life expectancy were projected with a lifetime horizon using regression formulae and US life tables, respectively. Quality of life adjustment, for the calculation of quality-adjusted life years, was applied across both periods using external inputs. Long-term survival was adjusted for strokes/systemic embolism (SE) events observed during initial follow-up. AF indicates atrial fibrillation.

Figure 2.

Scatterplot of incremental quality-adjusted life years (QALYs; x axis) and incremental costs (y axis) for atrial fibrillation monitoring vs control across 1000 replications of the study data with bootstrap resampling. The red circle indicates the base case point estimate. The dashed lines indicate willingness to pay thresholds of $50 000, $100 000, and $150 000 per QALY gained.

Figure 3.

Cost-effectiveness acceptability curve. Probability that the screening strategy was cost-effective based on bootstrap replications of the study sample is plotted across a range of willingness-to-pay (WTP) thresholds. The dashed green and red lines show these probabilities at WTP of $50 000 and $150 000 per quality-adjusted life year (QALY) gained, respectively.