Age for buddy-matching

[MPagel]

Currently the age of patients and their matched control is determined from the date-of-query and then binned into 5 year wide groupings.

However, this allows for a somewhat more non-deterministic pairing of patients and their matched negative controls than is likely intended, as people will age into a new age bracket at a different time than their negative controls. Buddies that are produced one year for a patient may not be eligible buddies in the subsequent year (and conversely, a new set of buddies may be made available).

Suggestion: use a fixed date as a reference for age determination for buddy matching. Study start date or projected study end date would be "logical" reference dates.

[MPagel]

If similar code is ported to a phenotype selection for future projects, I would personally find

        -- FLOOR shouldn't be needed in the CASE statement below, as integer divided by integer = truncated/floored integer. But inclusion of FLOOR makes intent more clear
        CASE FLOOR(datediff(year, d.birth_datetime, @arbitraryDate) / 5) 
		WHEN  0 THEN '0-4'
		WHEN  1 THEN '5-9'
		WHEN  2 THEN '10-14'
		WHEN  3 THEN '15-19'
		WHEN  4 THEN '20-24'
		WHEN  5 THEN '25-29'
		WHEN  6 THEN '30-34'
		WHEN  7 THEN '35-39'
		WHEN  8 THEN '40-44'
		WHEN  9 THEN '45-49'
		WHEN 10 THEN '50-54'
		WHEN 11 THEN '55-59'
		WHEN 12 THEN '60-64'
		WHEN 13 THEN '65-69'
		WHEN 14 THEN '70-74'
		WHEN 15 THEN '75-79'
		WHEN 16 THEN '80-84'
		WHEN 17 THEN '85-89'
		ELSE
			CASE SIGN(FLOOR(datediff(year, d.birth_datetime, @arbitraryDate)))
				WHEN 1 THEN '90+'
				ELSE NULL -- or 'not yet born'
			END
	END AS pt_age

cleaner, more legible and potentially less computationally intense as compared with

Phenotype_Data_Acquisition/PhenotypeScripts/N3C_phenotype_omop_redshift.sql

Lines 824 to 881 in 6d26382

	,CASE
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 0
	AND 4
	THEN '0-4'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 5
	AND 9
	THEN '5-9'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 10
	AND 14
	THEN '10-14'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 15
	AND 19
	THEN '15-19'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 20
	AND 24
	THEN '20-24'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 25
	AND 29
	THEN '25-29'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 30
	AND 34
	THEN '30-34'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 35
	AND 39
	THEN '35-39'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 40
	AND 44
	THEN '40-44'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 45
	AND 49
	THEN '45-49'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 50
	AND 54
	THEN '50-54'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 55
	AND 59
	THEN '55-59'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 60
	AND 64
	THEN '60-64'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 65
	AND 69
	THEN '65-69'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 70
	AND 74
	THEN '70-74'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 75
	AND 79
	THEN '75-79'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 80
	AND 84
	THEN '80-84'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) BETWEEN 85
	AND 89
	THEN '85-89'
	WHEN datediff(year, d.birth_datetime, CURRENT_DATE) >= 90
	THEN '90+'
	END AS pt_age

it would be further "optimized" by eliminating the text labels entirely and just collapsing division result greater than 18 into 18

...but I acknowledge that the current syntax gets the job done