Table 2.

Study group differences (net changes) in drinks per week over 3 years according to trajectory class.

	At-risk drinkers						Low-risk drinkers
	Light-stable		Medium-stable		High-decreasing		Very light-slightly increasing		Light-increasing
	IRR	(95% CI)	IRR	(95% CI)	IRR	(95% CI)	IRR	(95% CI)	IRR	(95% CI)
Month 3	0.97	(0.72–1.32)	0.93	(0.69–1.23)	0.81	(0.51–1.28)	0.94	(0.70–1.28)	1.02	(0.75–1.38)
Month 6	1.01	(0.71–1.44)	0.81	(0.58–1.14)	1.33	(0.68–2.61)	1.60	(1.12–2.28)	1.06	(0.80–1.40)
Year 1	1.08	(0.75–1.57)	0.85	(0.64–1.11)	1.11	(0.42–2.90)	1.04	(0.71–1.54)	0.87	(0.66–1.13)
Year 3	1.96	(1.14–3.37)	0.75	(0.47–1.17)	0.96	(0.84–1.89)	0.84	(0.58–1.20)	1.12	(0.79–1.60)

IRR, incidence rate ratio; CI, confidence interval. Trajectory classification quality for at-risk drinkers: entropy = 0.79, average latent class posterior probability range = 0.90–0.96. Trajectory classification quality for low-risk drinkers: entropy = 0.76, average latent class posterior probability range = 0.92–0.93. The bold values indicate study group differences with value of p < 0.05.