Visit_Name

Visit Name Variable Definition Table:

Tables that Reference this Variable:

Data Type Information:

Curation Notations:

There are discrepancies across the cohorts in coding of baseline and screening visits. In some studies, screening takes place during the baseline visit, whereas in other studies screening takes place during a separate precursor visit. 

• Baseline visits were labeled as M0 (month 0), with follow up visits as M1, M2, etc.
• Screening visits were labeled as SC.
• Visit 2 in BioFIND (week 2 visit) was labeled as M0_5.
  • If repeated record at the same visit #2 or #3 were added to visit label (e.g. M12, M12#2, etc.)

PPMI visits RS1, U01, U02, PW, ST were re-labeled using following approach:

1. RS1 – Re-screen visit was labeled SC#2
2. PW – Premature Withdrawal visits were aligned with closest to scheduled visit month difference calculated between dates of Baseline (M0) and PW visit using INFODT (e.g. if participant has M6 and M9 scheduled visits, PW visit would be M6 if month difference is 7 months).
3. U01, U02 – Unscheduled Visit 1 and 2 were aligned with closest to scheduled visit month difference calculated between dates of Baseline (M0) and unscheduled visit using INFODT. In “Biospecimen_analyses_CSF_abeta_tau_ptau.csv” and “DaTSCAN_SBR.csv” unscheduled visits are manually replaced (after transform1 automatic run) by “visit_name” from “PPMI Unexpected Visit Listings - DATSCAN and CSF data_May2019.xlsx” provided by Clinical Trials Statistical & Data Management Center, University of Iowa.
4. ST visits – Symptomatic Therapy visits were re-labeled with the regular visit label (e.g. V01=M3, V02=M6, V03=M9, V04=M12, etc.) using “ST Replaces Visit (STRPLCVS)” from ST_CATALOG.csv. If an ST visit replaced V01 or V03, then per protocol the subject was supposed to skip V02 or V04, respectively.  V01 and V03 in “STRPLCVS” were replaced by V02 and V04 only if V02 or V04 are missing, otherwise V01 and V03 were used (few cases where protocol was not followed).
5. 8 participants do not have STRPLCVS in ST_CATALOG.csv. For these the date difference was calculated, and the closest visit was used to replace ST (e.g. if PP-3067 has date difference 22 months then ST is M24; if PP-3078 has date difference 19 months then ST is M18; if PP-3653 has date difference 19 months then ST is M18).
6. The “LOG” visits were used to indicate that the time points are irrelevant for this particular data set (e.g. Smoking_and_alcohol_history.csv, Caffeine_history.csv, etc.), or for unscheduled/unknown visits where no date of visit is available.