Symptom burden and comorbidities impact the consistency of responses on patient-reported functional outcomes.

OBJECTIVE: To assess the influence of symptom intensity, mood, and comorbidities on patient-clinician agreement and the consistency of responses to functional patient-reported outcomes (PROs).

DESIGN: Two data sources were used. The first, a cross-sectional database of patients with breast cancer who completed functional PROs and were administered the FIM, was used to examine whether average pain intensity (as measured with an 11-point numeric rating scale [NRS]) and Rand Mental Health inventory scores differed among those rating their functional independence as different than clinicians. The second, a longitudinal database of 311 adults with late-stage lung cancer who completed the Activity Measure for Post Acute Care Computer Adaptive Test (AM PAC CAT) with differences between their expected and actual responses as reflected in their AM PAC CAT SEs.

SETTING: Two tertiary medical centers.

PARTICIPANTS: Data source #1, 163 women with stage IV breast cancer; data source #2, 311 adults with late-stage lung cancer.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Data source #1, FIM, pain NRS, Older Americans Resource Study activities of daily living subscale, Physical Function-10, Mental Health Inventory-17. Data source #2, AM PAC CAT and NRS symptom ratings.

RESULTS: Pain intensity was significantly higher when clinicians and patients disagreed regarding a patient's independence in the ability to transfer (NRS pain severity, 3.78 vs 2.40; P=.014), groom (3.71 vs 2.36, P=.009), bathe (3.76 vs 2.40, P=.016), and dress (3.09 vs 2.44, P=.034). The magnitude of AM PAC CAT SEs was significantly associated with the severity of participants' pain, dyspnea, and fatigue, as well as the presence of musculoskeletal disorders and coronary artery disease. Neither mood nor emotional distress was associated with clinician-patient agreement or AM PAC CAT SE.

CONCLUSIONS: Pain intensity is associated with disagreement between patients and clinicians about the patient's level of functioning. Moreover, physical symptoms (pain, dyspnea, fatigue) as well as specific medical comorbidities (musculoskeletal disorders, coronary artery disease), but not mood, are associated with inconsistency in patients' assessment of their functional abilities.