Health services use among children diagnosed with medium-chain acyl-CoA dehydrogenase deficiency through newborn screening: a cohort study in Ontario, Canada

Table 2 Age-stratified unadjusted relative (rate ratio) and absolute (rate difference) comparisons of rates of health services encounters in MCAD deficiency cohort versus screen negative cohort

Outcome and age group	Incidence rate ratio (IRR), MCAD deficiency cohort vs. screen negative cohort (95% CI)	Incidence rate difference (IRD), MCAD deficiency cohort vs. screen negative cohort, per child per year (95% CI)
Physician encounters
< 6 months	1.2 (1.1, 1.3)	4.2 (2.1, 6.4)
6 to < 12 months	1.6 (1.4, 1.8)	5.8 (4.1, 7.5)
12 to < 18 months	1.3 (1.1, 1.5)	2.9 (1.3, 4.5)
18 to < 24 months	1.7 (1.5, 1.9)	5.0 (3.4, 6.6)
2 to < 3 years	1.4 (1.2, 1.5)	2.0 (1.1, 2.9)
3 to < 4 years	1.5 (1.3, 1.7)	2.4 (1.3, 3.4)
≥ 4 years	1.5 (1.3, 1.7)	2.5 (1.4, 3.6)
Emergency department visits
< 6 months	1.9 (1.3, 2.7)	0.7 (0.2, 1.2)
6 to < 12 months	3.1 (2.4, 4.1)	1.7 (1.0, 2.4)
12 to < 18 months	2.6 (2.0, 3.5)	1.4 (0.8, 2.1)
18 to < 24 months	2.7 (2.0, 3.7)	1.3 (0.7, 2.0)
2 to < 3 years	2.1 (1.6, 2.9)	0.7 (0.3, 1.1)
3 to < 4 years	2.0 (1.4, 3.0)	0.5 (0.1, 0.9)
≥ 4 years	1.7 (1.1, 2.6)	0.3 (−0.03, 0.7)^a
Inpatient hospitalizations
< 6 months	1.6 (0.8, 3.5)^a	0.1 (− 0.1, 0.4)^a
6 to < 12 months	10.8 (6.1, 18.9)	0.5 (0.2, 0.9)
12 to < 24 months	9.6 (6.1, 15.0)	0.4 (0.2, 0.6)
2 to < 3 years	10.8 (6.3, 18.7)	0.3 (0.1, 0.5)
≥ 3 years	15.2 (9.7, 23.8)	0.4 (0.2, 0.5)

^aDifference not statistically significant, p > 0.05; all other rates were statistically significantly different between the two cohorts