2008. Do Health Experiences
in Depression Change Patients' Values?
CA Elnitsky, San Diego Healthcare System, LA Lenert, San Diego Healthcare System, CD Sherbourne, RAND Corp.
long-standing controversy exists regarding whether value measures, such as the
standard gamble (SG) and the time trade-off (TTO), elicited prior to treatment
will reflect individuals' values following treatment. This study's purpose was
to determine if the experience of depressive disorder changes individuals' risk
attitude and elasticity for time, components of their utilities.
Methods: This study used
two years of data from Partners in Care, a group-level randomized controlled
trial of quality improvement programs for depression. For 1,218 primary care
patients with depression, we examined single-item SG and TTO utilities at
baseline and 24 months. Logistic regressions identified factors associated with
patients' willingness to take risks in the gamble and trade time in the TTO and
examined trends in utilities of individuals with and without remission of
depression as measured by the Center for Epidemiologic Studies Depression
screener and selected items from the World Health Organization Composite
International Diagnostic Instrument.
Results: The proportion
of patients willing to take risks or trade time increased as depression symptoms
increased. Patients who continued to be depressed at 24 months were nearly 3
times more likely to be willing to assume risk or trade time than patients whose
depression remitted. Willingness to assume risk or trade time increased in
patients who continued to be depressed at 24 months. However the SG appeared to
lack sensitivity in patients whose depression remitted. Remission of depression
was associated with a decrease in willingness to trade time, as exected (95
percent CI = -.12, -.03), and a paradoxical increase in willingness to assume
risk. Among patients who continued to be depressed, increases in willingness to
assume risk were larger but not significantly different than increases in
willingness to trade time.
with depression appear to use a single-item SG measure differently at baseline
and 24 months. This could be due to changes in risk attitude resulting from
health experiences. Patients' elasticity for time appeared unchanged.
Impact: This study identified changes in values among patients experiencing depressive disorder. Changes in values can potentially confound the use of single-item SG utilities as measures of outcomes.