Meaning and purpose in life, happiness, and life satisfaction in cancer: systematic review with meta-analysis

Objective: To summarize current evidence on the potential cross‐sectional and longitudinal association between meaning or purpose in life and subjective happiness or life satisfaction among cancer patients. Methods: A systematic review with meta‐analysis and meta‐regression was conducted. CINAHL (via EBSCOhost), Embase, PubMed, and PsycINFO (via ProQuest) were searched from inception to 31 December 2022. In addition, manual searches were performed. The risk of bias in cross‐sectional and longitudinal studies was assessed using the Joanna Briggs Institute Checklist for Analytical Cross‐Sectional Studies and the Quality in Prognosis Studies tool, respectively. Certainty in the evidence was judged using the Grading of Recommendations, Assessment, Development, and Evaluations approach. Meta‐regressions and sensitivity analyses were performed to explore potential sources of heterogeneity. Results: We included 13 cross‐sectional studies, comprising 12 different samples, and a longitudinal study. A total of 4968 individuals with cancer were interviewed across included studies. Certainty in the evidence was judged as very low for all outcomes, which was associated to serious concerns on risk of bias and imprecision of the results, and very serious concerns on indirectness of evidence. The assessed studies showed a marked heterogeneity in terms of participants' clinical (i.e., disease stage) and sociodemographic factors. A lack of reporting of these clinical and sociodemographic aspects were also evident among included studies. Conclusions: The wide number of methodological flaws detected in this systematic review preclude to make any clinical recommendation. More rigorous high‐quality observational studies should guide future research on this topic.