Comprehensive geriatric assessment for older adults undergoing surgery: A protocol for a systematic review and meta-analysis

Registration

The protocol for this systematic review has been registered with the International Prospective Register of Systematic Reviews (PROSPERO; registration number CRD420261322154).

Study design

This systematic review protocol has been developed in accordance with the Preferred Reporting Items for Systematic Reviews & Meta-Analyses Protocols (PRISMA-P) guidelines.¹⁹ A structured template detailing all required protocol components has been utilised, as outlined in Extended Data Material 1. The completed systematic review and any meta-analysis will be reported in line with the 27-item PRISMA checklist.²⁰ The review will be conducted in accordance with the Cochrane Handbook for Systematic Reviews of Interventions.²¹ To ensure a robust assessment of intervention effects, inclusion will be limited to randomised study designs, including individually randomised controlled trials, cluster randomised trials and quasi-randomised controlled trials.

Search strategy

Searches will be conducted in MEDLINE, Embase, the Cumulative Index of Nursing and Allied Health Literature (CINAHL), PsycINFO and the Cochrane Central Register of Controlled Trials within the Cochrane Library (CENTRAL). The search strategy will build on that used in a previously published 2018 systematic review and meta-analysis.³ Both MeSH terms and free-text keywords relating to older adults, comprehensive geriatric assessment, and surgery will be adapted for use across the relevant databases (Extended Data Material 2). The search will be restricted to studies published from 2017 onwards, as the purpose of this review is to update the earlier systematic review and meta-analysis. Trials from any surgical specialty, in either the emergency or elective setting, will be eligible for inclusion. Trials included in the previous review will be incorporated alongside newly identified evidence.³ Reference lists of all eligible studies will be screened to identify any additional relevant publications. No language restrictions will be applied, and translation will be sought for studies published in languages other than English.

Eligibility criteria

Trials will be included that meet the following inclusion criteria.

Population

The review will include adults aged 65 years and older who are admitted to hospital. While there is no universally agreed numerical threshold for defining older age, 65 years is commonly used in clinical and research settings.²² Eligible participants will include patients admitted for elective or emergency surgery, as well as those hospitalised with acute medical conditions or injuries requiring close monitoring and management by a surgical service. As perioperative studies commonly include mixed-age populations, studies will be eligible if the sample is considered representative of older adults. This will be defined pragmatically as those in which the majority of participants are aged ≥65 years, or where the mean or median age reflects an older population. Where available, data specific to participants aged ≥65 years will be extracted. Sensitivity analyses will be conducted to evaluate the impact of including mixed-age populations. This approach will align with the 2018 Cochrane review, with added transparency in eligibility decisions.

Intervention

We will include studies in which a CGA is undertaken in hospital. CGA is a multidimensional, multidisciplinary diagnostic and therapeutic process conducted to determine the medical, psychological and functional problems of older adults with frailty so that a coordinated and integrated plan for treatment and follow-up can be developed.¹³ CGA may be provided at different points during the hospital admission, including prior to surgery, following surgery, or continuously throughout the inpatient stay. We will include studies in which a Geriatrician, geriatric nurse or another physician trained in geriatric assessment conducted a CGA. The 2017 Cochrane review by Ellis et al. will be used as the reference standard for defining the components of CGA across included trials.¹³ This review describes CGA as comprising clinical leadership, structured assessment, multidisciplinary team meetings, goal setting, involvement of patients and carers in goal setting, outpatient follow-up, appropriate ward environment, adequate time allocation, specialty knowledge, experience and competence, and the individualisation of treatment plans as outlined by O’Shaughnessy et al.²³

Exclusion criteria

Studies that assess only a single component of CGA rather than a multidimensional assessment will be excluded. Enhanced Recovery After Surgery (ERAS) programmes will not be included, as CGA is not a routine element of these interventions. Studies that do not report any of the predefined outcomes of interest will also be excluded.

Comparison

Patients receiving standard operative care under surgical specialties. Standard operative care will be outlined in each individual study.

Outcome variables

The primary outcome will be functional status measured at hospital discharge and at follow-up time points reported in the included trials. Any validated instrument that measures independence in activities of daily living (ADLs) across time points will be accepted. Secondary outcomes will include length of stay (LoS), days at home alive (defined as being alive and residing in one’s own home at follow-up), mortality, incidence of unscheduled hospital readmission, cognitive function, incidence of adverse events and postoperative complications (cardiovascular, thromboembolic, infectious, neurological and respiratory complications). Outcomes will be recorded at hospital discharge and follow-up time points reported in trials.

Study selection and data extraction

Screening

All references identified through the search strategy will be exported to Covidence, where duplicate records will be removed. Two reviewers (CMG and ÍO’S) will independently screen titles and abstracts to assess eligibility against the predefined inclusion criteria. Studies deemed potentially eligible will proceed to full-text review. If a disagreement about inclusion arises, both authors will meet to come to a consensus. If consensus cannot be reached, a third and fourth reviewer (RG and EA) will be consulted.

Data synthesis and analysis

Two reviewers (CMG and ÍO’S) will independently extract data from included studies; data from trials in the previous version of this review will also be extracted. The data gathered will include trial authors, year of publication, study population, sample size, type of interventions provided, controls provided, outcomes measured and duration of follow up. Data will be collated using a predesigned Microsoft Excel data extraction template. If consensus cannot be reached, a third and fourth reviewer (RG and EA) will be consulted.

Statistical analysis will be performed using Review Manager Software (version 5.4) for meta-analysis. The primary outcome of functional status, we will calculate the intervention effect using mean differences (MD) and 95% confidence intervals (CI) where trials used the same method of measurement. Standardised MD and 95% CI will be applied where trials used different validated measures of functional status. The same approach will be applied for all continuous secondary outcome measures. Risk ratios with 95% CIs will be calculated to determine the intervention effect for dichotomous secondary outcomes. If a pooled meta-analysis is not possible, findings will be reported narratively, summarising the available evidence across included studies.

Quality assessment

Risk of bias (RoB) will be evaluated for all included trials, including those from the earlier review, using the Cochrane RoB 2 tool.²⁴ Two independent reviewers (CMG and ÍO’S) will evaluate each trial’s RoB. Risk of bias will be evaluated across five predefined domains. Within each domain, reviewers respond to a series of signalling questions, which inform an overall judgement of “low risk of bias,” “some concerns,” or “high risk of bias.” If a disagreement about RoB arises, both authors will come to a consensus. If a consensus cannot be reached, third and fourth authors will be contacted (RG and EA). The certainty of the evidence will be evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework by two independent reviewers (CMG and RG).²⁵

Public and patient involvement

The protocol will be presented to the Patient and Public Involvement (PPI) stakeholder panel of older adults and family caregivers at the University of Limerick on 24^th June 2026 to explore outcomes that are most important to them and to identify key components they believe should be incorporated into the intervention.