Abstract
To better connect non-emergent 911 callers to appropriate care, Washington, DC, routed low-acuity callers to nurses. Nurses could provide non-emergent transportation to a health centre, recommend self-care or return callers to the traditional 911 system. Over about one year, 6,053 callers were randomized (1:1) to receive a business-as-usual response (ncontrol = 3,023) or further triage (ntreatment = 3,030). We report on seven of nine outcomes, which were pre-registered (https://osf.io/xderw). The proportion of calls resulting in an ambulance dispatch dropped from 97% to 56% (β = −1.216 (−1.324, −1.108), P < 0.001), and those resulting in an ambulance transport dropped from 73% to 45% (β = −3.376 (−3.615, −3.137), P < 0.001). Among those callers who were Medicaid beneficiaries, within 24 hours, the proportion of calls resulting in an emergency department visit for issues classified as non-emergent or primary care physician (PCP) treatable dropped from 29.5% to 25.1% (β = −0.230 (−0.391, −0.069), P < 0.001), and the proportion resulting in the caller visiting a PCP rose from 2.5% to 8.2% (β = 1.252 (0.889, 1.615), P < 0.001). Over the longer time span of six months, we failed to detect evidence of impacts on emergency department visits, PCP visits or Medicaid expenditures. From a safety perspective, 13 callers randomized to treatment were eventually diagnosed with a time-sensitive illness, all of whom were quickly triaged to an ambulance response. These short-term effects suggest that nurse-led triage of non-emergent calls can safely connect callers to more appropriate, timely care.
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Data availability
The data analysed in this paper were provided by DC’s FEMS, Office of the Chief Technology Officer and DHCF and contain protected health information. To protect privacy, we cannot publicly post individual-level data. Qualified researchers and relevant approvals including ethical approval can request access to the de-identified data about this trial from the corresponding author. A formal contract will be signed, and an independent data protection agency should oversee the sharing process to ensure the safety of the data.
Code availability
All code used to produce this analysis is publicly available at https://github.com/thelabdc/FEMS-911NurseTriageLine-public.
Change history
27 June 2024
A Correction to this paper has been published: https://doi.org/10.1038/s41562-024-01921-9
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Acknowledgements
This work would not be possible without the support of M. Bowser (mayor), K. Donahue (city administrator), R. Young (former city administrator), S. Quinney (director of The Lab @ DC), G. M. Dean (retired fire chief), FEMS, the Office of Unified Communications, the DHCF, the FQHCs, the DC Primary Care Association, the Department of Health and the Office of the Deputy Mayor for Public Safety and Justice. We thank the following for their time and assistance in making this evaluation possible: M. Baisley, A. Beaton, V. Bishop, D. Braman, R. Breslin, S. Brown, I. Bucksell, J. Coombs, D. Corcoran, T. Curtis, O. Dedner, J. Doleac, N. Donnelly, J. Duff, T. Dutta, L. Edmonson, B. Egar, K. Gan, H. Gil, A. Grady, J. Greenberg, K. Holmes, E. Holve, A.-T. Huang, A. Huberts, T. Kavaleri, D. Kornfield, E. Koshkin, B. Kreiswirth, B. Krucoff, K. Liebowitz, M. MacCarthy, K. Minnich, A. Mauro, L. Nesbitt, C. Nguyen, C. Nwaete, P. Oandasan, K.Y. Oh, J. Reed, M. Reed, S. Roque, C. Scholsberg, N. Smith, D. Stanescu, P. Testa, T. Thangalvadi, W. Turnage, J. Wedeles, D. Weinroth, J. Weissfeld, O. Whittaker, M. Williamson, S. Willig and J. Wobbleton. We especially thank M. A. Bates, N. Choudhry and B. Özler for reviewing the pre-analysis plan and M. Welch for her substantive and project management contributions during the review process. The intervention as a whole was funded by general appropriations from the District of Columbia. R.P.H., as the medical director of DC FEMS, was also funded through DC appropriations. C.H., K.H.W., R.T.M. and D.Y. were funded through the Laura and John Arnold Foundation (now Arnold Ventures). R.A.J. was funded through the ABF/JPB Foundation Access to Justice Scholars programme for time supporting the work. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
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Conceptualization: C.H., R.P.H., R.T.M., K.H.W. and D.Y. Methodology: C.H., R.T.M., K.H.W. and D.Y. Visualization: R.A.J. and K.H.W. Coding and analysis—original analysis: R.A.J. and K.H.W. Coding and analysis—review and supplemental: R.A.J., R.T.M. and K.H.W. Project administration: C.H. and R.P.H. Supervision: C.H. and R.T.M. Writing—original draft: C.H., R.A.J. and K.H.W. Writing—review and editing: C.H., R.P.H., R.A.J., R.T.M., K.H.W. and D.Y.
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R.P.H. was during the commission of this study the medical director of DC FEMS and draws a salary from the District of Columbia. The remaining authors declare no competing interests.
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Nature Human Behaviour thanks Stefan Morreel and Armann Ingolfsson for their contribution to the peer review of this work.
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Extended data
Extended Data Fig. 1 Overall counts of treated and control group callers aggregated to the monthly level.
The figure shows the raw counts of treatment and control group callers for each of the eleven months in the study period. We see a sharp rise after the triage line was expanded to 24 hours per day.
Extended Data Fig. 2 Balance plot: treatment and control group (Medicaid beneficiary sample).
The figure shows the standardized mean difference for each attribute between the treatment and control group, which helps us compare variables on different scales (for example, years versus percentages).
Extended Data Fig. 3 Detailed outcomes of the safety analysis.
The flow chart shows a low incidence of safety events.
Supplementary information
Supplementary Information
Four sections of supplementary discussion: safety analysis results, matching to Medicaid beneficiaries, departures from the pre-analysis plan and key sections of code.
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Wilson, K.H., Johnson, R.A., Hatzimasoura, C. et al. A randomized controlled trial evaluating the effects of nurse-led triage of 911 calls. Nat Hum Behav 8, 1276–1284 (2024). https://doi.org/10.1038/s41562-024-01889-6
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DOI: https://doi.org/10.1038/s41562-024-01889-6