Intolerance of uncertainty (IU) is widely accepted as a transdiagnostic vulnerability factor for a range of mental health problems. It is considered a transsituational vulnerability factor associated with a range of responses to different stressful life situations. The aim of this systematic review and meta-analysis is to examine the association between IU and specific psychological responses to the COVID-19 pandemic and the moderators of this relationship drawn from IU research and other studies on COVID-19.
The studies included were as follows: (i) English-language articles published in peer-reviewed journals or thesis/dissertations; (ii) reporting specific psychological impacts of COVID-19; (c) reporting IU; (iii) case-control studies, prospective cohort studies, experimental studies and cross-sectional studies of large populations and (iv) reporting correlation coefficients between the variables of interest. Studies on participants with a diagnosis of neurological and/or organic impairment were excluded. The databases searched were Google Scholar, PubMed, ScienceDirect, and ProQuest, up until 31 December 2022. The risk of bias was assessed using the Risk of Bias Utilized for Surveys Tool (ROBUST, Nudelman et al., 2020). Sensitivity analysis was conducted using the one-study remove method, and studentized residuals and Cook's distance were examined. A random effects model was used.
We examined the association between IU and COVID-19-related psychological impacts across 85 studies from 22 countries (N = 69,997; 64.95% female; mean sample age, 32.90 ± 9.70). There was no evidence of publication bias. We found a medium and positive association between IU and COVID-19-related psychological impacts (N = 69,562, r = 0.35, k = 89, 95% CI [0.32, 0.37]), which was independent of the IU measure used or whether the psychological impact was measured in relation to the virus alone or broader aspects of the pandemic. It was also independent of severity, publication year, sample type and size, study quality, age and sample levels of anxiety, depressive symptoms, stress, mental well-being and social support. However, the observed association varied significantly between countries and country income levels (stronger among low-incomes) and across genders (stronger among males) and was stronger for measures with greater reliability and more items, but lower among samples with more people who had been exposed to COVID-19.
The findings support that IU is a higher order transsituational vulnerability factor related to cognitive, behavioural and distress responses during the pandemic. Limitations include English-language-only sources, reliance on a wide range of measures that were coded using a novel system and variable risk of bias across studies. The implications are considered in relation to the management of psychological consequences of major situational stressors experienced at a global scale, but the variations at a national and socioeconomic level also have implications for different or localized stressors at a regional or community level.