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Health Care Science 2023, 2(2): 82-93 https://doi.org/10.1002/hcs2.30
Original Article | Open Access | Issue | Published: 13 March 2023

Retrospective matched cohort study of incidence rates and excess length of hospital stay owing to pressure injuries in an Asian setting

Show Author's Information Nicholas Graves1 ( ),  Raju Maiti2,  Fazila Abu Bakar Aloweni3,  Ng Yi Zhen4,  Ang Shin Yuh3,  Priya Bishnoi4,  Tze Tec Chong3,  David Carmody3,  Keith Harding4,5
Health Services and Systems Research, Duke‐NUS Medical School, Singapore, Singapore
Centre for Quantitative Medicine, Duke‐NUS Medical School, Singapore, Singapore
Singapore General Hospital, Singapore, Singapore
Skin Research Institute of Singapore, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
Wound Care Innovation for the Tropics Programme, Singapore, Singapore
Keywords:
costs, health care‐acquired pressure injury, incidence rates, attribution methods
Cite this article:
Graves N, Maiti R, Aloweni FAB, et al. Retrospective matched cohort study of incidence rates and excess length of hospital stay owing to pressure injuries in an Asian setting. Health Care Science, 2023, 2(2): 82-93. https://doi.org/10.1002/hcs2.30
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Abstract Full text About this article
Background

Little is known about stage 1 and 2 pressure injuries that are health care‐acquired. We report incidence rates of health care‐acquired stage 1 and stage 2 pressure injuries, and, estimate the excess length of stay using four competing analytic methods. We discuss the merits of the different approaches.

Methods

We calculated monthly incidence rates for stage 1 and 2 health care‐acquired pressure injuries occurring in a large Singapore acute care hospital. To estimate excess stay, we conducted unadjusted comparisons with a control cohort, performed linear regression and then generalized linear regression with a gamma distribution. Finally, we fitted a simple state‐based model. The design for the cost attribution work was a retrospective matched cohort study.

Results

Incidence rates in 2016 were 0.553% (95% confidence interval [CI] 0.55, 0.557) and 0.469% (95% CI 0.466, 0.472) in 2017. For data censored at 60 days’ maximum stay, the unadjusted comparisons showed the highest excess stay at 17.68 (16.43‐18.93) days and multi‐state models showed the lowest at 1.22 (0.19, 2.23) days.

Conclusions

Poor‐quality methods for attribution of excess length of stay to pressure injury generate inflated estimates that could mislead decision makers. The findings from the multi‐state model, which is an appropriate method, are plausible and illustrate the likely bed‐days saved from lowering the risk of these events. Stage 1 and 2 pressure injuries are common and increase costs by prolonging the length of stay. There will be economic value investing in prevention. Using biased estimates of excess length of stay will overstate the potential value of prevention.


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Abstract
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About this article

Retrospective matched cohort study of incidence rates and excess length of hospital stay owing to pressure injuries in an Asian setting

Show Author's information Nicholas Graves1 ( ), Raju Maiti2, Fazila Abu Bakar Aloweni3, Ng Yi Zhen4, Ang Shin Yuh3, Priya Bishnoi4, Tze Tec Chong3, David Carmody3, Keith Harding4,5
Health Services and Systems Research, Duke‐NUS Medical School, Singapore, Singapore
Centre for Quantitative Medicine, Duke‐NUS Medical School, Singapore, Singapore
Singapore General Hospital, Singapore, Singapore
Skin Research Institute of Singapore, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
Wound Care Innovation for the Tropics Programme, Singapore, Singapore

Abstract

Background

Little is known about stage 1 and 2 pressure injuries that are health care‐acquired. We report incidence rates of health care‐acquired stage 1 and stage 2 pressure injuries, and, estimate the excess length of stay using four competing analytic methods. We discuss the merits of the different approaches.

Methods

We calculated monthly incidence rates for stage 1 and 2 health care‐acquired pressure injuries occurring in a large Singapore acute care hospital. To estimate excess stay, we conducted unadjusted comparisons with a control cohort, performed linear regression and then generalized linear regression with a gamma distribution. Finally, we fitted a simple state‐based model. The design for the cost attribution work was a retrospective matched cohort study.

Results

Incidence rates in 2016 were 0.553% (95% confidence interval [CI] 0.55, 0.557) and 0.469% (95% CI 0.466, 0.472) in 2017. For data censored at 60 days’ maximum stay, the unadjusted comparisons showed the highest excess stay at 17.68 (16.43‐18.93) days and multi‐state models showed the lowest at 1.22 (0.19, 2.23) days.

Conclusions

Poor‐quality methods for attribution of excess length of stay to pressure injury generate inflated estimates that could mislead decision makers. The findings from the multi‐state model, which is an appropriate method, are plausible and illustrate the likely bed‐days saved from lowering the risk of these events. Stage 1 and 2 pressure injuries are common and increase costs by prolonging the length of stay. There will be economic value investing in prevention. Using biased estimates of excess length of stay will overstate the potential value of prevention.

Keywords: costs, health care‐acquired pressure injury, incidence rates, attribution methods

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Publication history
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Publication history

Received: 29 September 2022
Accepted: 28 November 2022
Published: 13 March 2023
Issue date: April 2023

Copyright

© 2023 The Authors.

Acknowledgements

ACKNOWLEDGMENTS

The Wound Care Innovation for the Tropics (WCIT) Program and Wound Care Registry teams supported this work. This research is supported by the Agency for Science, Technology and Research (A*STAR) under its Industry Alignment Fund—Pre‐Positioning Program (IAF‐PP) grant number H1X/01/a0/OX9 as part of the Wound Care Innovation for the Tropics (WCIT) Program.

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This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

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