Proguanil and atovaquone use is associated with lower colorectal cancer risk: a nationwide cohort study

Table 2 Hazard ratios and 95% confidence intervals of colorectal cancer associated with proguanil/atovaquone use among individuals with family history

	Individuals, n	Person-years	CRC diagnoses, n	IR, per 10,000 person-year	Crude			Adjusted^a
	Individuals, n	Person-years	CRC diagnoses, n	IR, per 10,000 person-year	HR	95% CI	P value	HR	95% CI	P value
Ever use of proguanil/atovaquone
No	168,170	1,185,525	1431	12.07	1			1
Yes	16,817	120,203	112	9.32	0.76	0.63–0.92	0.004	0.76	0.62–0.93	0.006
Dose of proguanil/atovaquone
<6 cDDD	10,748	72,288	72	9.96	0.80	0.63–1.02	0.071	0.82	0.64–1.05	0.112
7–12 cDDD	3729	28,019	24	8.57	0.73	0.48–1.10	0.133	0.67	0.44–1.03	0.070
>12 cDDD	2340	19,896	16	8.04	0.66	0.40–1.10	0.113	0.62	0.37–1.04	0.071
P for trend										<0.001
Duration of proguanil/atovaquone
Less than 1 week	10,642	71,148	72	10.12	0.83	0.66–1.05	0.118	0.84	0.66–1.07	0.155
1week–1year	3188	22,995	21	9.13	0.78	0.52–1.19	0.255	0.78	0.51–1.19	0.248
>1year	2987	26,060	19	7.29	0.63	0.40–0.99	0.046	0.57	0.36–0.90	0.016
P for trend										<0.001

CRC colorectal cancer, IR incidence rate, HR hazard ratio, CI confidence intervals, COPD chronic obstructive pulmonary disease, IBD inflammatory bowel disease, CCI Charlson Comorbidity Index score
^aAdjusted for age at index, sex, education, birth country, income, history of inflammatory bowel disease, COPD, obesity, outpatient visits, history of colonoscopy, use of aspirin, use of statin, and CCI

ISSN: 1741-7015