MDD

Minutes (courtesy Patience Gallagher)

Minutes:

• PV
• • Reminder of the original concept:
  • • Group patients on SSRIs into 3 groups based on whether their medication had a high, medium or low affinity for the serotonin transporter - determine if there is a dose response for bleeding events
    • • Use this design instead of a case-control
      • Decided against self-matched analysis because that approach is best when the exposure is intermittent and has immediate, transient effects
    • Doing this study is important, as there is limited data available in the literature, but the prior is high (Smoller et al., 2009, Archives of Internal Medicine)
    • Outcome of interest: Bleeds (e.g. stroke, GI bleeds)
  • Vivian, Roy and Victor have worked on various iterations of the same general idea – the group needs to decide on final approach.
  • The Plan:
  • • Use a test of proportions (Zak has a reference for this that he can distribute)
    • • (This approach is kind of like a Chi Square)
    • Use only patients on monotherapy
    • • We are not looking at dose of medication, just where the prescription falls on the affinity spectrum, which will be divided into three groups (high, medium and low affinity)
    • Start with a patient’s first exposure to AD (not first event) à look forward 6 months. If event doesn’t happen in those six months, restart the clock.
    • • Although six months is the primary window of time, a sensitivity analysis of 30 days will also be done.
    • If a patient switches categories (goes from high to medium affinity drug) they are censored. However, if a patient switches from one drug to another within the same affinity category, they stay in the analysis.
    • As a control, we’ll look at patients with: MI, DVT, prostate cancer, colon cancer, asthma, and breast cancer (?)
    • The 3 groups (high, medium and low affinity) will be compared on visit intensity, age, gender
    • • As long as visit intensity isn’t associated with just one of the categories of affinities, it should not be a confounder.
  • Victor has written most of the code needed for these analyses, so he will incorporate the ideas discussed today and bring the results to the meeting next week.
  • Additional issues to consider:
  • • Using another psychotropic comparator as a negative control would be good, but difficult to do.
    • Look at depression response (do patients actually get better while on AD?)
    • Collaboration with the Stroke Service at MGH (Dr. Furie) – They are interested in collaborating – Roy will follow up with them.
    • • They have a comprehensive stroke database (that includes imaging data) that could be incredibly useful for the PV component – And reciprocally, our AD exposure info/algorithms would be beneficial to them.
      • Protocol will need to be amended to incorporate their data in our analyses