Table 4.

Associations between placement in OHC (ages 0–18) and premature all-cause mortality (ages 19–65), before and after propensity score matching.

	HR (95% CI)	n	Person-years	Number of events (deaths)
Before matching, crude modela	2.71 (2.38–3.09)	14,502	639,348	1403
Before matching, adjusted modelac	2.32 (1.99–2.70)	14,004	618,400	1354
After matching, with replacementbd	2.43 (1.89–3.13)	2075	89,532	352
After matching, without replacementbd	1.95 (1.39–2.73)	1468	64,223	207

HR=Hazard ratios; CI=Confidence interval.

Bold face = p < 0.001.

^aComparing individuals placed in OHC to the rest of the population.

^bCompared to control group. Matching variables include gender, household dysfunction, family socioeconomic conditions, and environmental factors prior to placement.

^cModel adjusted for same variables as matching variables.

^dNearest neighbour matching in which each OHC placed individual is matched to a control from the rest of the population that is nearest in terms of propensity scores. With replacement means that always the closest match will be used where a control can be used more than once, whereas in procedures without replacement each control can be used only once.