add_prior_observation

add_prior_observation(
    table,
    cdm,
    *,
    index_date='cohort_start_date',
    prior_observation_name='prior_observation',
    prior_observation_type='days',
)

Add days (or date) of prior observation in the current observation period at index_date.

Parameters

Name	Type	Description	Default
table	Any	Ibis table with person_id or subject_id and index_date.	required
cdm	Cdm	CDM reference (observation_period).	required
index_date	str	Column name for index date (default “cohort_start_date”).	'cohort_start_date'
prior_observation_name	str	Output column name (default “prior_observation”).	'prior_observation'
prior_observation_type	str	“days” or “date” (default “days”).	'days'

Returns

Name	Type	Description
	ibis.expr.types.Table	Table with prior_observation column.