Latent Class Analysis of Symptom Burden Among Seriously Ill Adults at the End of Life

Serious illness is characterized by high symptom burden that negatively affects quality of life (QOL). Although palliative care research has highlighted symptom burden in seriously ill adults with cancer, symptom burden among those with noncancer serious illness and multiple chronic conditions has been understudied. Latent class analysis is a statistical method that can be used to better understand the relationship between severity of symptom burden and covariates, such as the presence of multiple chronic conditions. Although latent class analysis has been used to highlight subgroups of seriously ill adults with cancer based on symptom clusters, none have incorporated multiple chronic conditions.

The objectives of this study were to (a) describe the demographic and baseline characteristics of seriously ill adults at the end of life in a palliative care cohort, (b) identify latent subgroups of seriously ill individuals based on severity of symptom burden, and (c) examine variables associated with latent subgroup membership, such as QOL, functional status, and the presence of multiple chronic conditions.

A secondary data analysis of a palliative care clinical trial was conducted. The latent class analysis was based on the Edmonton Symptom Assessment System, which measures nine symptoms on a scale of 0-10 (e.g., pain, fatigue, nausea, depression, anxiousness, drowsiness, appetite, well-being, and shortness of breath). Clinically significant cut-points for symptom severity were used to categorize each symptom item in addition to a categorized total score.

Three latent subgroups were identified (e.g., low, moderate, and high symptom burden). Lower overall QOL was associated with membership in the moderate and high symptom burden subgroups. Multiple chronic conditions were associated with statistically significant membership in the high symptom burden latent subgroup. Older adults between 65 and 74 years had a lower likelihood of moderate or high symptom burden subgroup membership compared to the low symptom burden class.

Lower QOL was associated with high symptom burden. Multiple chronic conditions were associated with high symptom burden, which underlines the clinical complexity of serious illness. Palliative care at the end of life for seriously ill adults with high symptom burden must account for the presence of multiple chronic conditions.