I am analyzing CCAE dataset in IMEDS lab.
My discussion item is about observation_period table.
Also, in another thread brought about this problem - differences in how you generate this table impact your results of any given SQL script. (Regenstrief operating on 36month window vs. allowing maximum 30 d of silence to close observation period)
Relationship to PAYER_PLAN_PERIOD is also of great importance. What if your EHR data have no payer data to work it at all.
The table is defined as:
“The Observation Period table is designed capture the time intervals in which data are being
recorded for the Person. An Observation Period is the span of time when a Person is expected to have clinical events recorded. “
For a country like UK, the observation
periods for all citizens will be something like: from BIRTH to DEATH since they
are “insured” all the time. For US, the table is mostly derived from payor_plan
tables and is more complicated.
I see in CCAE dataset has sometimes drug data without
a visit. I looked at the ETL for the IMEDS CCAE dataset, and it does not
clearly define what events are considered when deriving this table.
The CCAE IMEDS ETL document says:
Patient Status during an Observation Period in the Truven claims data
is available from the Enrollment tables. Enrollment Detail (ccaeT) includes records that indicate a person’s enrollment for each month for the period covered by the claims data.
Enrollment entries are consolidated by combining records that indicate
continuous enrollment over a period of time start and end dates to cover the
period. If enrollment data indicates a person’s coverage did not extend through
the entire duration covered by claims data, then multiple Observation Periods
are recorded to capture all periods of coverage with corresponding start and
end dates.
The consolidation is done through the following steps:
- Records for each person are sorted in an ascending order of dtStart (Start Date).
- Periods of continuous enrollment consolidated by combining monthly records and
recording the Start Date (dtStart) for the first period as the Observation
start date and end date for the last period as the Observation end date. If the
time between the end of one enrollment period and the start of the next is 32
days or less, treat this as continuous enrollment.
·
No records are added to cover gaps in coverage.
But it does not state when it “combines montly records” whether it considers labs as records or labsORvisitORdiagnosis as record. What is meant by event/record is crucial.
There is also an associated Achilles_heel report that looks at “events
outside observation periods”.
The table observation_period is not listed in chapter of CDM v5 specs as Standardized Derived Elements. But in most cases, it is derived and we should be clear about how exactly it is derived and have it derived consistently accros sites.
No EHR has a tab for “entering patient observation periods”.
E.g., “When did you approximately move-in to central Wisconsin?”
I am looking at “silent patients” as patients that seem to be healthy (no events, but have insurance coverage) and rules that generate observation_periods are very important for that
(since I don’t have access to generally all-insured population (like UK’s CPRD) 
)
