Table 3.

Testing Hypothesis 1: aggregate costs, cost differences, and difference-in-differences savings estimate for a pool of 100 drivers over 18 months

Study subgroup	Estimated cost for 100 drivers BEFORE	Estimated cost for 100 drivers AFTER	Cost difference (After − Before)
Controls	$344,231	$530,925	$186,694
95% CI	(291,465, 404,707)	(411,120, 676,368)	(56,153, 339,195)
Diagnosed	$324,409	$358,061	$33, 652
95% CI	(265,927, 391,084)	(292,625, 430,829)	(−54,686, 122,784)
Cost difference (Controls − Diagnosed)	$19,822	$172,864	$153,042
95% CI	(−62,337, 100,716)	(31,722, 331,151)	(−5,352, 330,525)

Table reports results from 10 000 empirical bootstrap iterations using costs in the 18 months before, and the 18 months after, the PSG/matching date. Costs are adjusted from dollars at the time of the study to 2018 dollars using the Personal Consumption Expenditure (PCE) index for health care expenses. The lower right table cell provides the difference-in-differences estimate of the aggregate cost savings. This estimate is statistically significant at the p = .06 level.