Distinct Physical Function Profiles in Older Adults Receiving Cancer Chemotherapy

Abstract

Context: Although physical function is an important patient outcome, little is known about changes in physical function in older adults receiving chemotherapy (CTX).

Objectives: Identify subgroups of older patients based on changes in their level of physical function; determine which demographic and clinical characteristics were associated with subgroup membership; and determine if these subgroups differed on quality-of-life (QOL) outcomes.

Methods: Latent profile analysis was used to identify groups of older oncology patients (n = 363) with distinct physical function profiles. Patients were assessed six times over two cycles of CTX using the Physical Component Summary score from the Short Form 12. Differences, among the groups, in demographic and clinical characteristics and QOL outcomes were evaluated using parametric and nonparametric tests.

Results: Three groups of older oncology patients with distinct functional profiles were identified: Well Below (20.4%), Below (43.8%), and Above (35.8%) normative Physical Component Summary scores. Characteristics associated with membership in the Well Below class included the following: lower annual income, a higher level of comorbidity, being diagnosed with depression and back pain, and lack of regular exercise. Compared with the Above class, patients in the other two classes had significantly poorer QOL outcomes.

Conclusion: Almost 65% of older oncology patients reported significant decrements in physical function that persisted over two cycles of CTX. Clinicians can assess for those characteristics associated with poorer functional status to identify high-risk patients and initiate appropriate interventions.

Keywords: Physical function; chemotherapy; comorbidity; latent class analysis; older adults.

Figure 1

Trajectores of physical component summary function scores for the three physical function latent classes