Table 3.

Multivariate logistic regression analysis on the association of IWanttheKit (IWTK) risk score and prevalence of sexually transmitted infections (STIs) (chlamydia, gonorrhoea and trichomoniasis) by gender

Characteristics	Categories	OR (95% CI) in the final model
		Female	Male*
Age (years)	<20	3.15 (1.58 to 6.30)	N.S.
	20–29	1.56 (0.92 to 2.66)	N.S.
	≥30	1.00	N.S.
Race	White	1.00	1.00
	African-American	2.63 (1.52 to 4.58)	5.69 (1.96 to 16.59)
	Other	2.92 (1.52 to 5.62)	4.01 (1.09 to 14.68)
Risk score category†	‘Low risk’	1.00	1.00
	‘Medium risk’	2.23 (1.41 to 3.52)	1.84 (0.42 to 8.11)
	‘High risk’	4.22 (2.08 to 8.58)	3.88 (0.85 to 17.69)

^*Variable ‘risk score’ in the model for male participants was not statistically significant in the multivariate regression model. This variable was forced in the model for male participants.

^†Risk score category: defined by prevalence of STIs for each gender. Risk score of 0–4 was categorised as ‘low risk’, risk score of 5–7 as ‘medium risk’ and risk score of 8–10 as ‘high risk’ for female participants; risk score of 0–2 was categorised as ‘low risk’, risk score of 3–6 as ‘medium risk’ and risk score of 7–10 as ‘high risk’ for male participants.

N.S., not included in the model since it was not statistically significant.