Table 4.

Risk of damage accrual by HDAS episode duration

HDAS episode duration	Odds of accruing damage
	Unadjusted		Adjusted for observation timea
	OR (95% CI)	p value	OR (95% CI)	p value
Never experienced HDAS	1	Not applicable	1	Not applicable
Cumulative HDAS duration
≥1 day and < 1 year	1.64 (0.90–2.97)	0.12	1.48 (0.49–4.08)	0.46
≥1 year and < 2 years	1.70 (0.76–3.83)	0.19	1.27 (0.60–2.39)	0.49
2 years or more	5.55 (2.88–10.71)	< 0.001*	1.80 (1.08–2.97)	0.02*
Mean duration of HDAS episode
≥1 day and < 1 year	2.31 (1.41–3.81)	< 0.001*	2.12 (0.88–5.00)	0.09
≥1 year and < 2 years	1.81 (0.71–4.62)	0.30	0.93 (0.27–2.31)	0.88
2 years or more	6.37 (2.30–17.66)	< 0.001*	1.60 (0.91–2.67)	0.08

OR odds ratio, CI confidence interval

*Statistically significant at p < 0.05

^aAdjusted for observation time modelled as a categorical variable (< 5 years, 5–< 10 years, and 10+ years)