BackgroundThe COVID-19 pandemic has worsened pre-existing vulnerabilities among older Syrian refugees in Lebanon, potentially impacting their mental health. This study aimed to identify predictors of poor mental health amongst older Syrian refugees living in Lebanon during the pandemic.MethodsThis study used repeated cross-sectional data from a multi-wave telephone survey (September 2020-March 2022). It was conducted among Syrian refugees aged 50 years or older from households that received assistance from a humanitarian organization. Poor mental health was defined as a Mental Health Inventory-5 score of 60 or less. Its trend over time was assessed using growth curve model; and, its predictors were identified using wave one data, through backwards stepwise logistic regression. The model’s internal validation was conducted using bootstrapping.FindingsThere were 3,229 participants (median age=56 [IQR=53-62]) and 47.5% were female. At wave one, 76.7% had poor mental health, and this increased to 89.2% and to 92.7% at waves three and five, respectively (β=0·52; 95% CI: 0·44-0·63; p-value<0.001). Predictors for poor mental health were younger age, food insecurity, water insecurity, lack of legal status documentation, irregular employment, higher intensity of bodily pain, having debt, and having chronic illnesses. The final model demonstrated good discriminative ability and calibration.InterpretationMental health predictors were related to basic needs, rights and financial barriers. These allow humanitarian organizations to identify high risk individuals, organizing interventions, and addressing root causes to boost resilience and well-being among older Syrian refugees in Lebanon.FundingELRHA’s Research for Health in Humanitarian Crisis Programme.Research in contextEvidence before this studyA search was conducted on PubMed and Google Scholar for studies published between February 1, 2020 and June 20, 2023, using the search terms “Syrian Refugees”, “Mental Health”, and “Prediction Model”, including all article types with no time constraints or language restrictions. We found that few previous prognostic models for Syrian refugees have been developed exclusively among participants at high risk of poor mental health, such as widowed women, Syrian refugees with post-traumatic stress disorder, or those who experienced ambiguous loss. Older adults were underrepresented in these studies, which had small sample sizes and focused primarily on inter-relational factors. Therefore, their effectiveness in predicting outcomes for this highly vulnerable group, which faces distinct circumstances, may be constrained due to their development based on incomparable samples and contexts. Furthermore, none were developed during the COVID-19 pandemic. Overall, the search highlighted the need for research into the specific vulnerabilities and risk factors for mental health faced by the community of older Syrian refugees in Lebanon, as the existing models do not appear to be applicable to this group.Added value of this studyThe study developed a prognostic model to predict the risk of poor mental health amongst older Syrian refugees in Lebanon during the COVID-19 pandemic, using predictors that covered economic, social and health factors. Data were collected using a multi-wave panel study. Most participants had poor mental health that increased over the course of the study. Younger age, food insecurity, water insecurity, lack of legal status documentation, irregular employment, higher intensity of bodily pain, having debt, and having multiple chronic illnesses were predictors of poor mental health. These findings are consistent with previous literature on associations between these vulnerabilities and poor mental health amongst refugees.Implications of all the available evidenceThe study provides evidence that the population of older Syrian refugees in Lebanon faces multiple vulnerabilities and were largely at risk for poor mental health, which increased during the COVID-19 pandemic. Vulnerabilities identified in this study as predictors of poor mental health indicate that it will be necessary to engage with humanitarian sectors outside of health such as food assistance, water, sanitation and hygiene (WASH) and legal assistance programs in order to support mental health in older Syrian refugees.