Table 3

Parent-reported medically attended injury and injury-associated health service presentation rates (per 100 person-years) for intervention and control groups

Measure	Measurement time point	Control group rate per 100 person-years (n events) Baseline n=393 12 months n=349 24 months n=312	Intervention group rate per 100 person-years (n events) Baseline n=354 12 months n=286 24 months n=260	Primary analysis		Multiple imputation analysis
Measure	Measurement time point			Adjusted* incidence rate ratio (95% CI)	P value	Adjusted* incidence rate ratio (95% CI)	P value
Medically attended injury	Baseline†	10.2 (10)	13.6 (12)	1.31 (0.26 to 6.62)	0.74‡	1.14 (0.33 to 3.87)	0.84
	Year 1	23.7 (66)	27.3 (57)	0.89 (0.51 to 1.56)	0.68	1.05 (0.64 to 1.70)	0.86‡
	Year 2	32.0 (84)	31.5 (59)	0.98 (0.57 to 1.70)	0.95	Not applicable	**
Family doctor presentations due to injury	Baseline†	3.1 (3)	9.0 (8)	4.85 (0.46 to 50.79)	0.19	7.70 (0.88 to 676.70)	0.37
	Year 1	5.0 (14)	9.1 (19)	1.13 (0.36 to 3.54)	0.83	1.22 (0.45 to 3.30)	0.70‡
	Year 2	5.7 (15)	5.3 (10)	1.01 (0.31 to 3.25)	0.99	1.13 (0.45 to 2.85)	0.80
Urgent care or walk-in centre presentations due to injury	Baseline†	0.0 (0)	1.1 (1)	Not applicable§	0.99‡¶	Not applicable§	**
	Year 1	2.5 (7)	3.8 (8)	1.69 (0.23 to 12.41)	0.61	Not applicable	**
	Year 2	4.6 (12)	3.2 (6)	0.60 (0.19 to 1.96)	0.40¶	0.56 (0.20 to 1.55)	0.26¶
Emergency department presentations due to injury	Baseline†	9.2 (9)	14.7 (13)	0.63 (0.08 to 5.32)	0.67	0.62 (0.15 to 2.56)	0.51
	Year 1	15.1 (42)	14.4 (30)	0.97 (0.52 to 1.81)	0.94¶	Not applicable	**
	Year 2	22.5 (59)	23.5 (44)	0.97 (0.50 to 1.91)	0.94	0.92 (0.54 to 1.57)	0.77‡
Hospital admissions due to injury	Baseline†	1.0 (1)	2.3 (2)	0.55 (0.00 to 509.0)	0.87	Not applicable	**
	Year 1	1.4 (4)	0.5 (1)	Not applicable§	**	Not applicable	**
	Year 2	2.3 (6)	1.1 (2)	0.01 (0.0001 to 1.06)	0.053¶	0.09 (0.01 to 1.43)	0.088¶

Completion of each three monthly follow-up injury questionnaire represented 0.25 years of data. For year 1, for example, any participant could contribute 0.25, 0.50, 0.75 or 1.0 years of injury follow-up data.
*The adjusted model controlled for: number of siblings under the age of 16 years; maternal age at the time of birth of the first child; the Index of Multiple Deprivation (IMD) of the home postcode, whether the family lived in a single-adult household; the corresponding baseline variable (where collected); and the matched wards factor.
†Baseline rates were based on the number of events that were reported to have occurred in the 3 months prior to the intervention.
‡The model did not initially converge so the ‘Matched wards’ factor was removed to enable convergence.
§The ratio of events is 0:1 and the upper 95% CI cannot be defined.
¶A Poisson model was used.
**Model did not converge following removal of matched wards.