A natural experimental study of improvements along an urban canal: impact on canal usage, physical activity and other wellbeing behaviours

Table 3 Mixed-effects negative binomial regression results for the total number of people. Models adjusted for day, time of day and precipitation

Time point	Total number of people (median per observation period)		Model results at each follow-up
Time point	Intervention group	Comparison group	Total number of observation periods in model	IRR	95% CI	Robust standard error	p-value	Random effect variance (site)
Baseline	51 (4)	65 (2)	–	–	–	–	–	–
7 months	148 (13.5)	117 (5)	72	1.67	1.44–1.95	0.13	< 0.001*	5.16e-34
12 months ^a	142 (11.5)	88 (3)	72	2.10	1.79–2.48	0.17	< 0.001*	8.75e-34
24 months	154 (13.5)	99 (4)	70 ^b	2.42	1.80–3.24	0.36	< 0.001*	5.76e-33

CI confidence interval, IRR incidence rate ratio
^a Primary outcome; ^b Two observation periods were cancelled at the intervention site due to ethical concerns regarding observer safety
*Statistically significant at p < 0.05 (z-test, two-tailed)

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