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Keywords: survival analysis, cox proportional hazard, multi state model, panel study, occupational health
Panel studies involve taking repeated measurements on individuals and monitoring event statuses over time. Depending on the goals of the study, a variety of analysis methods may be appropriate for addressing specific research questions. We present a survey of statistical methods that can be used to analyze such data. Survival analysis is particularly effective at modeling event relative risk in the presence of censored observation time. For repeated events of the same type, random subject effects can be included to take into account within subject variation. Multi-state models can characterize the entire event progression history when more than one status variable is tracked over time. Poisson regression focuses on rate of occurrence of specific events. We offer applications of each aforementioned method to a cohort study on the severity of low back pain in manufacturing and production industries. Assumptions and requirements of each method are discussed as well as inference and interpretation. This analysis is particularly useful for learning about these types of disorders as researchers can develop better job risk assessment to benefit industry.