Influence of social determinants of health on patients with advanced lung cancer: a prospective cohort study

Introduction Socioeconomic factors with an influence on human health are known as social determinants of health (SDH). There are some SDH studies in patients with lung cancer, but important exposures such as social isolation and loneliness have not been adequately investigated. This study will assess the influence of SDH, particularly social isolation and loneliness, on patients with advanced lung cancer in Japan. Methods and analysis The inclusion criteria for this prospective cohort study will be as follows: a diagnosis of advanced lung cancer; unsuitability for curative surgery; and willingness to participate. The primary outcome will be the initial choice of treatment and the secondary outcomes will be overall survival, changes in disease staging or performance status, route to diagnosis and place of death. The exposures will be social isolation, loneliness, employment, insurance type, education and dementia. The study enrolment period will be 1 year and the follow-up duration will be 2 years. The log-rank test will be used to compare overall survival between patients when grouped according to the study exposures and multivariate analysis will be performed using Cox proportional hazards regression. The X-2 test will be used to compare the initial treatment, changes in disease stage and place of death, and logistic regression will be used for multivariate analysis of these factors. A p value <0.05 will be considered statistically significant. Ethics and dissemination This study has been approved by the Institutional Review Board at Hyogo Prefectural Amagasaki General Medical Center (No 29-164). A manuscript summarising the outcome of this study will be submitted to a peer-reviewed journal and the data will be presented at conferences.