Exclusive cigar smoking in the United States and smoking-related diseases: A systematic review

Table 6 Relative risks and 95%CIs by current amount smoked¹

Study	Cigars per day	RR (95%CI) lung cancer	RR (95% CI) COPD	RR (95%CI) IHD	Adjustment factors
CPS I[23]
	1-2	0.90 (0.54 to 1.66)	1.39 (0.74 to 2.38)	0.98 (0.91 to 1.07)	Age
	3-4	2.36 (1.49 to 3.54)	1.78 (0.89 to 3.18)	1.06 (0.96 to 1.16)
	5+	3.40 (2.34 to 4.77)	1.03 (0.37 to 2.23)	1.14 (1.03 to 1.24)
CPS II[32]
Age 30-74 years	1			1.18 (0.76 to 1.82)	Age+2
	2-3			1.43 (1.03 to 1.99)
	4+			1.33 (0.95 to 1.86)
Age 75+ years	1			1.07 (0.64 to 1.78)
	2-3			0.72 (0.45 to 1.16)
	4+			1.03 (0.70 to 1.51)
DORN[27]3
Age 55-64	< 5	0.64 (0.15 to 2.69)		0.84 (0.70 to 1.01)	None
	5+	3.74 (1.53 to 9.10)		0.98 (0.78 to 1.24)
Age 65-74	< 5	1.32 (0.65 to 2.69)		1.07 (0.94 to 1.23)
	5+	1.83 (0.78 to 4.27)		1.21 (1.02 to 1.45)
KAISER[13]
	< 5	1.57 (0.67 to 3.66)	1.30 (0.93 to 1.81)	1.20 (1.03 to 1.40)	Age+4
	5+	3.24 (1.01 to 10.40)	2.25 (1.39 to 3.65)	1.56 (1.21 to 2.01)
KAUFMAN[33]
	1-4			0.90 (0.30 to 2.70)	Age+5
	5+			1.70 (0.60 to 4.80)
NLMS[17]
	< 1	0.74 (0.08 to 7.26)			Age+6
	1+	4.18 (2.34 to 7.46)
SADOW[30]7
	1	1.62			None
	2	4.51
	3	4.38
	4+	2.54

¹Relative to never smoking.

²Adjusted also for education, hypertension, BMI, exercise, alcohol, environmental tobacco smoke and vitamin C.

³Estimated from data provided.

⁴For lung cancer and chronic obstructive pulmonary disease adjusted also for race, body mass index (BMI), history of diabetes, alcohol and occupational exposure; for ischaemic heart disease adjusted also for race, BMI, history of diabetes, alcohol, education, systolic blood pressure and serum cholesterol.

⁵Adjusted for religion, education, ethnicity, personality, family history of myocardial infarction, doctor visits, geography, physical activity, BMI, and treatment for diabetes, cholesterol, hypertension and chest pain.

⁶Adjusted also for sex, race, education and survey year.

⁷95% CI not available, RRs estimated from data provided. RRs: Relative risks; COPD: Chronic obstructive pulmonary disease; IHD: Ischaemic heart disease.