Valuing the outcomes of treatment: do patients and their caregivers agree?

BACKGROUND: Treatment outcomes are an important determinant of patients' treatment preferences. Although studies have examined how well surrogates agree with patients' preferences for specific treatment interventions, agreement regarding the valuation of health states as treatment outcomes is unknown.
METHODS: Cross-sectional cohort study consisting of in-home interviews with 193 persons 60 years or older and seriously ill with cancer, congestive heart failure, or chronic obstructive pulmonary disease and their caregivers. Patients were asked whether, facing an exacerbation of illness, they would find a series of health states acceptable as a result of treatment (a rating of "unacceptable" meant they would prefer to die than to receive treatment). Caregivers were asked whether they would find these states acceptable for the patient.
RESULTS: There was 80% or greater agreement for health states that were overall rated either acceptable (current health, mild memory impairment, mild pain, or other symptoms) or unacceptable (coma). There was 58% to 62% agreement (kappa = 0.10-0.25) about states with more severe physical or cognitive impairment. When disagreement occurred, caregivers were more likely to rate the state as acceptable. There was 61% to 65% agreement (kappa = 0.20-0.28) about states with severe pain or other symptoms. When disagreement occurred, caregivers and patients were equally likely to rate the state as acceptable.
CONCLUSIONS: Patient-caregiver agreement about the acceptability of health states with functional or cognitive impairment, severe pain, or other symptoms was poor. Caregivers making surrogate decisions based on considerations of treatment outcomes may not effectively represent patients' preferences.