Association between preoperative anxiety and postoperative delirium in older patients: A systematic review and meta-analysis

Background: Postoperative delirium (POD) is a common complication following surgery, being associated with multiple adverse outcomes and higher health care costs. Preoperative anxiety has been suggested to precipitate POD. We aimed to explore the association between preoperative anxiety and POD in older surgical patients.

Methods: Electronic databases including MEDLINE (via PubMed), EMBASE (via Embase.com), Web of Science Core Collection, Cumulative Index to Nursing and Allied Health Literature (CINAHL Complete; via EBSCOhost) and clinical trial registries were systematically searched to identify prospective studies examining preoperative anxiety as a risk factor for POD in older surgical patients. Quality was assessed using the Joanna Briggs Institute Critical Appraisal Checklist for Cohort Studies. The association was summarized with odds ratios (ORs) and 95% confidence intervals (CIs) using DerSimonian-Laird random-effects meta-analyses.

Results: Eleven studies with a total of 1691 participants aged between 63.1-82.3 years proved eligible. Five studies theoretically defined preoperative anxiety, and the most utilized assessment instrument for preoperative anxiety was Anxiety subscale of Hospital Anxiety and Depression Scale (HADS-A). Preoperative anxiety was significantly associated with POD when using dichotomized measures (OR= 2.17, 95%CI: 1.01-4.68, I²=54%, Tau²=0.4, n=5) and the subgroup analysis of HADS-A (OR= 3.23, 95%CI: 1.70-6.13, I²=0, Tau²=0, n=4). No association was found when using continuous measurements (OR= 0.99, 95%CI: 0.93-1.05, I²=0, Tau²=0, n=4), nor in the subgroup analysis of STAI-6 (six-item version of state scale of Spielberger State-Trait Anxiety Inventory, OR= 1.07, 95%CI: 0.93-1.24, I²=0, Tau²=0, n=2). The overall quality of included studies was moderate to good.

Conclusions: There is an uncertain association between preoperative anxiety and POD in older surgical patients, and the results need to be interpreted cautiously due to the ambiguity in conceptualization and measurement instruments used for preoperative anxiety.