The University of Southampton
University of Southampton Institutional Repository

Nurse staffing levels and patient outcomes: a systematic review of longitudinal studies

Nurse staffing levels and patient outcomes: a systematic review of longitudinal studies
Nurse staffing levels and patient outcomes: a systematic review of longitudinal studies
Background: the contribution of registered nurses towards safe patient care has been demonstrated in many studies. However, most of the evidence linking staffing levels to outcomes is cross-sectional with intrinsic limitations including an inability to establish that presumed cause (staffing) precedes the effect. No reviews have summarised longitudinal studies considering nurse staffing and patient outcomes.

Objectives: to identify and assess the evidence for an association between nurse staffing levels, including the composition of the nursing team, and patient outcomes in acute care settings from longitudinal studies.

Methods: we undertook a systematic review of studies where the association between nurse staffing with patient outcomes was assessed in a longitudinal design. Studies with repeated cross-sectional analyses were excluded unless a difference-in-difference design was used. We searched Medline, CINAHL, Embase and the Cochrane Library up to February 2022. We used the ROBINS-I tool to assess risk of bias. We synthesised results in a tabular form and a narrative grouped by outcome.

Results: 27 papers were included. Studies were conducted in a variety of settings and populations, including adult general medical/surgical wards and adult and neonatal intensive care units. Staffing measures were operationalised in a variety of different ways, making direct comparisons between studies difficult and pooled estimates impossible. Most studies were either at serious (n = 12) or critical (n = 5) risk of bias, with only 3 studies at low risk of bias. Studies with the most risk of bias were judged as likely to underestimate the effect of higher registered nurse staffing. Findings are consistent with an overall picture of a beneficial effect from higher registered nurse staffing on preventing patient death. The evidence is less clear for other patient outcomes with a higher risk of bias, but in general the proposition that higher registered nurse staffing is likely to lead to better patient outcomes is supported. Evidence about the contribution of other nursing staff groups is unclear.

Conclusion: the causal relationship between low registered nurse staffing and mortality is plausible and these estimates of relationships from longitudinal studies provide further support. To address residual uncertainties, future studies should be conducted in more than one hospital and using standardised measures when reporting staffing levels.

Tweetable abstract: Having more registered nurses on hospital wards is causally linked to reduced mortality – new review shows there is little room for doubt @ora_dall @workforcesoton @turnel.
Inpatients, Longitudinal studies, Nursing staff, Personnel staffing and scheduling, Workforce
0020-7489
Dall'ora, Chiara
4501b172-005c-4fad-86da-2d63978ffdfd
Saville, Christina
2c726abd-1604-458c-bc0b-daeef1b084bd
Rubbo, Bruna
dc31cd48-3d84-41ab-a8b8-351c9914dca4
Turner, Lesley
7c4a1fe5-21a1-4634-a1cc-0230322603d1
Jones, Jeremy
270b303b-6bad-4be7-8ea0-63d0e8015c91
Griffiths, Peter
4689c22e-33f4-4163-898b-a97281c08e74
Dall'ora, Chiara
4501b172-005c-4fad-86da-2d63978ffdfd
Saville, Christina
2c726abd-1604-458c-bc0b-daeef1b084bd
Rubbo, Bruna
dc31cd48-3d84-41ab-a8b8-351c9914dca4
Turner, Lesley
7c4a1fe5-21a1-4634-a1cc-0230322603d1
Jones, Jeremy
270b303b-6bad-4be7-8ea0-63d0e8015c91
Griffiths, Peter
4689c22e-33f4-4163-898b-a97281c08e74

Dall'ora, Chiara, Saville, Christina, Rubbo, Bruna, Turner, Lesley, Jones, Jeremy and Griffiths, Peter (2022) Nurse staffing levels and patient outcomes: a systematic review of longitudinal studies. International Journal of Nursing Studies, 134, [104311]. (doi:10.1016/j.ijnurstu.2022.104311).

Record type: Review

Abstract

Background: the contribution of registered nurses towards safe patient care has been demonstrated in many studies. However, most of the evidence linking staffing levels to outcomes is cross-sectional with intrinsic limitations including an inability to establish that presumed cause (staffing) precedes the effect. No reviews have summarised longitudinal studies considering nurse staffing and patient outcomes.

Objectives: to identify and assess the evidence for an association between nurse staffing levels, including the composition of the nursing team, and patient outcomes in acute care settings from longitudinal studies.

Methods: we undertook a systematic review of studies where the association between nurse staffing with patient outcomes was assessed in a longitudinal design. Studies with repeated cross-sectional analyses were excluded unless a difference-in-difference design was used. We searched Medline, CINAHL, Embase and the Cochrane Library up to February 2022. We used the ROBINS-I tool to assess risk of bias. We synthesised results in a tabular form and a narrative grouped by outcome.

Results: 27 papers were included. Studies were conducted in a variety of settings and populations, including adult general medical/surgical wards and adult and neonatal intensive care units. Staffing measures were operationalised in a variety of different ways, making direct comparisons between studies difficult and pooled estimates impossible. Most studies were either at serious (n = 12) or critical (n = 5) risk of bias, with only 3 studies at low risk of bias. Studies with the most risk of bias were judged as likely to underestimate the effect of higher registered nurse staffing. Findings are consistent with an overall picture of a beneficial effect from higher registered nurse staffing on preventing patient death. The evidence is less clear for other patient outcomes with a higher risk of bias, but in general the proposition that higher registered nurse staffing is likely to lead to better patient outcomes is supported. Evidence about the contribution of other nursing staff groups is unclear.

Conclusion: the causal relationship between low registered nurse staffing and mortality is plausible and these estimates of relationships from longitudinal studies provide further support. To address residual uncertainties, future studies should be conducted in more than one hospital and using standardised measures when reporting staffing levels.

Tweetable abstract: Having more registered nurses on hospital wards is causally linked to reduced mortality – new review shows there is little room for doubt @ora_dall @workforcesoton @turnel.

Text
Nurse staffing levels and patient outcomes a systematic review of longitudinal studies - Accepted Manuscript
Download (319kB)
Text
1-s2.0-S0020748922001407-main - Version of Record
Available under License Creative Commons Attribution.
Download (497kB)

More information

Accepted/In Press date: 9 June 2022
e-pub ahead of print date: 16 June 2022
Published date: 1 July 2022
Additional Information: Funding Information: this study is funded by the NIHR [Health and Social Care Delivery Research ( NIHR128056 ) and Applied Research Collaboration Wessex]. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
Keywords: Inpatients, Longitudinal studies, Nursing staff, Personnel staffing and scheduling, Workforce

Identifiers

Local EPrints ID: 467960
URI: http://eprints.soton.ac.uk/id/eprint/467960
ISSN: 0020-7489
PURE UUID: b9e6f96f-fa03-469b-a2f5-2678bc60c021
ORCID for Chiara Dall'ora: ORCID iD orcid.org/0000-0002-6858-3535
ORCID for Christina Saville: ORCID iD orcid.org/0000-0001-7718-5689
ORCID for Bruna Rubbo: ORCID iD orcid.org/0000-0002-1629-8601
ORCID for Lesley Turner: ORCID iD orcid.org/0000-0003-1489-3471

Catalogue record

Date deposited: 26 Jul 2022 17:06
Last modified: 17 Mar 2024 03:57

Export record

Altmetrics

Contributors

Author: Chiara Dall'ora ORCID iD
Author: Bruna Rubbo ORCID iD
Author: Lesley Turner ORCID iD
Author: Jeremy Jones
Author: Peter Griffiths

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×