Costs of fall injuries in the STRIDE study: an economic evaluation of healthcare system heterogeneity and heterogeneity of treatment effect

David A Ganz; Thomas M Gill; David B Reuben; Shalender Bhasin; Nancy K Latham; Peter Peduzzi; Erich J Greene

doi:10.1186/s12962-023-00459-3

Costs of fall injuries in the STRIDE study: an economic evaluation of healthcare system heterogeneity and heterogeneity of treatment effect

Cost Eff Resour Alloc. 2023 Aug 2;21(1):49. doi: 10.1186/s12962-023-00459-3.

Authors

David A Ganz^{1

2

3}, Thomas M Gill⁴, David B Reuben⁵, Shalender Bhasin⁶, Nancy K Latham⁶, Peter Peduzzi⁷, Erich J Greene⁷

Affiliations

¹ Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. dganz@mednet.ucla.edu.
² Geriatric Research, Education and Clinical Center, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA. dganz@mednet.ucla.edu.
³ RAND Corporation, Santa Monica, CA, USA. dganz@mednet.ucla.edu.
⁴ Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA.
⁵ Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
⁶ Boston Claude D. Pepper Older Americans Independence Center, Research Program in Men's Health: Aging and Metabolism, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
⁷ Yale Center for Analytical Sciences, Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA.

Abstract

Objectives: The Strategies to Reduce Injuries and Develop Confidence in Elders (STRIDE) Study cluster-randomized 86 primary care practices in 10 healthcare systems to a patient-centered multifactorial fall injury prevention intervention or enhanced usual care, enrolling 5451 participants. We estimated total healthcare costs from participant-reported fall injuries receiving medical attention (FIMA) that were averted by the STRIDE intervention and tested for healthcare-system-level heterogeneity and heterogeneity of treatment effect (HTE).

Methods: Participants were community-dwelling adults age ≥ 70 at increased fall injury risk. We estimated practice-level total costs per person-year of follow-up (PYF), assigning unit costs to FIMA with and without an overnight hospital stay. Using independent variables for treatment arm, healthcare system, and their interaction, we fit a generalized linear model with log link, log follow-up time offset, and Tweedie error distribution.

Results: Unadjusted total costs per PYF were $2,034 (intervention) and $2,289 (control). The adjusted (intervention minus control) cost difference per PYF was -$167 (95% confidence interval (CI), -$491, $216). Cost heterogeneity by healthcare system was present (p = 0.035), as well as HTE (p = 0.090). Adjusted total costs per PYF in control practices varied from $1,529 to $3,684 for individual healthcare systems; one system with mean intervention minus control costs of -$2092 (95% CI, -$3,686 to -$944) per PYF accounted for HTE, but not healthcare system cost heterogeneity.

Conclusions: We observed substantial heterogeneity of healthcare system costs in the STRIDE study, with small reductions in healthcare costs for FIMA in the STRIDE intervention accounted for by a single healthcare system.

Trial registration: Clinicaltrials.gov (NCT02475850).

Keywords: Economic evaluation; Fall prevention; Heterogeneity of treatment effect.

Associated data

ClinicalTrials.gov/NCT02475850

Abstract

Associated data

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