Persistence with pharmacological treatment in the specialist mental healthcare of patients with severe mental disorders (Persistence of treatment in mental patients)

Study type

• Study topic:
  Disease /health condition

  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Drug utilisation
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Anatomical Therapeutic Chemical (ATC) code:
  (N06A) ANTIDEPRESSANTS

  ANTIDEPRESSANTS

  (N05A) ANTIPSYCHOTICS

  ANTIPSYCHOTICS

  (N03A) ANTIEPILEPTICS

  ANTIEPILEPTICS

Population studied

• Short description of the study population:
  Patients with schizophrenia, bipolar disorder, and unipolar depression in Lombardy who in an index period (January 1st to December 31st 2007) have received at least one psychiatric service and have one of the diagnoses of interest and have taken at least one prescription appropriate (antidepressants for depression, antipsychotics for schizophrenia, stabilizers medications/antipsychotics for bipolar disorder).
• Age groups:
  • Adult and elderly population (≥18 years)

    • Adults (18 to < 65 years)

      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)

      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
• Estimated number of subjects:
  11797

Study design details

• Main study objective:
  To measure persistence with pharmacological treatment in the specialist mental healthcare of patients with schizophrenia, bipolar disorder, and unipolar depression in Lombardy, a region of 10 million inhabitants located in the northernmost part of Italy.
• Outcomes:
  Persitence with pharmacological treatment
• Data analysis plan:
  Time to lack of persistence with initial pharmacological treatment was the outcome measure employed in this study. It was defined as a gap of at least 30 days between subsequent medication fills. The proportion of patients who were not persistent with drug treatment was calculated for the three cohorts of patients with depression, schizophrenia and bipolar disorder. Kaplan-Meier survival curves were used to examine time to treatment discontinuation. In order to identify potential determinants of discontinuation, three Cox regression models, one for each diagnostic cohort, were fitted, and adjusted hazard ratios with 95% confidence intervals were estimated according to level of exposure variables. The results were considered significant at p<0.05. Data management and statistical analysis were carried out using SAS statistical package(SAS Institute, Cary, NC), version 9.1, the PHREG procedurewas used to fit the Cox regression models.