Table 3.

Association of days without medication between fills and prior persistence on other chronic medications with antidepressant persistence

	Total No.	Proportion persistent to antidepressant %	Baseline prediction model a + additional measure RR (95% CI)
CHILDREN
Days without medication between fills (n=6,828) b
0 days	3,707	64	1.00 (Reference)
1 – 9 days	2,001	58	0.91 (0.87, 0.95)
10–30 days	1,120	46	0.72 (0.67, 0.77)
ADULTS
Days without medication between fills (n=33,212) b
0 days	17,375	70	1.00 (Reference)
1 – 9 days	10,101	64	0.92 (0.90, 0.93)
10–30 days	5,736	52	0.74 (0.72, 0.76)
Prior persistence on other chronic medication (n=5,755) c
Persistent on other medication	4,583	55	1.00 (Reference)
Not persistent on other medication	1,172	40	0.73 (0.68, 0.79)

RR (risk ratio), CI (confidence interval)

^aBaseline prediction model for children: age, initial low dose, recurrent major depressive disorder, anxiety diagnosis, substance use, outpatient visits, provider specialty; adults: age, antidepressant class, initial low dose, depression severity, substance use, outpatient visits, prescription count, high and mid-potency opiate usage, hypotension, provider specialty

^bMeasure of the number of days without medication between the first and second antidepressant fill, based on dispensing dates and days supply, among children and adults with a second antidepressant fill

^cPrior persistence on other medications measured whether an individual remained on an anti-hyperlipidemic, antihypertensive, bone-density regulator, or chronic asthma medication for at least 6 months in the year prior to antidepressant initiation