Overall Survival and Survival Time by Palliative Performance Scale: A Retrospective Cohort Study in Thailand

The palliative performance scale (PPS) is a useful tool for predicting the survival time of palliative patients and for multidisciplinary teams in designing an appropriate care plan for patients and their families. This study aimed to (1) assess the survival time of palliative patients, (2) examine the factors associated with survival time and (3) investigate the proportion of patients whose survival time matched the time proposed by existing literature, within the Thai population.

A retrospective cohort study was conducted with data drawn from five hospitals in one of the north-east provinces in Thailand. The study population comprised patients with a palliative diagnosis (ICD10: Z51.5) who had registered in one of the five hospitals between 1 October 2015 and 30 September 2017. Kaplan-Meier survival analysis was used to assess overall survival time and an extended Cox regression model to identify predictors of survival.

Of the 2792 registered patients, 1163 were included in the analysis. Most patients were male (55.62%), with a mean age of 64.59 years (±15.38), and were covered by the universal coverage insurance (77.72%). Approximately half (56.23%) of the participants had cancer and about a quarter (27.13%) had an initial PPS result of 30. The overall median survival time was 14 days (mean = 64.08, 95% CI: 12-16). Three significant predictors for survival included sex, hospital and initial PPS score.

The survival time of palliative patients was relatively short. Sex, hospital and initial PPS were significant predictors of survival. The median survival time by PPS was similar to the values reported by the previous study but proportion of correct prediction was low. Therefore, it might be necessary to investigate the survival time of palliative patients by country independently.