Assess effects of antidepressant compliance on healthcare and workplace costs.

Using workplace survey data for 2 large employers’ healthcare claims (2004-2006), patient selection criteria considered depression diagnosis and antidepressant claims history. Employed respondents working in the past month were categorized by Medication Possession Ratio into compliance groups by quartiles; bottom/top quartiles were defined as compliant/non-compliant. Direct (medical/drug) costs were measured as insurer payments to providers; indirect (absenteeism/presenteeism) costs were based on one-month recall of workplace performance (hours worked/missed, self-rated performance), estimated as (hours missed x self-reported hourly income). Annualized, inflation-adjusted (2006) costs were compared between compliant/non-compliant groups using multivariate models controlling for baseline characteristics. Analyses were conducted for all patients and a subsample of diagnosed depression patients.

Among all patients (n=1,224), medical costs were numerically lower for compliant vs. non-compliant patients ($4,857 vs. $5,926, p=0.221); drug costs were significantly higher for compliant patients ($2,329 vs. $1,570, p=0.001). Indirect costs were not statistically different between compliant/non-compliant patients ($22,278 vs. $20,714, p=0.237). Among the depression subgroup (N=488), medical costs were numerically lower for compliant vs. non-compliant patients ($5,005 vs. $7,630, p=0.152) while drug costs were numerically higher for compliant patients ($2,550 vs. $1,829, p=0.153). Absenteeism costs were 30% lower for compliant patients ($7,725 vs. $11,040, p=0.038); presenteeism costs were not significantly different ($19,079 vs. $17,457, p=0.441).

Absenteeism costs decrease significantly with compliance among depressed patients as do medical costs (not significantly). Further research is warranted regarding reason for poor antidepressant compliance and influence of compliance on costs.