Relationship between Smoking and Acute Mountain Sickness: A Meta-Analysis of Observational Studies

Table 2

Characteristics of included studies.

Study	Final altitude (MASL)	Design		Smoking	AMS	Smoking adjustment
Wu et al., 2012	4552 MASL (4292–4905 MASL), Qinghai-Tibet railroad; occupational cohort	Cohort study	382	Smoking status: (i) No smoker; (ii) Smoker < 20 cig/d; (iii) Smoker 20 cig/d; (iv) Smoker > 20 cig/d	LLS ≥ 4	Absent
Li et al., 2011	(2900–4300 MASL); Qinghai Tibet plateau; military cohort	Cohort study	3727	Smoking status: (i) No current smoker; (ii) Current smoker	SSQ	Present
Wagner et al., 2008	4419 MASL (2550–4419) Mt. Whitney, California, USA; Hikers	Cross-sectional	886	Smoking status: (i) Smoker; (ii) Nonsmoker	LLS ≥ 3	Absent
You et al., 2012	4300 MASL (2860–5250 MASL); Military cohort	Cohort study	314	Smoking status: (i) Not current smoker; (ii) Current smoker	LLS ≥ 4	Present
Vinnikov et al., 2014	4000 MASL (3800–4200 MASL) Tyan Shan Mountains, Kyrgyzstan; Occupational cohort	Nested case-control (1 : 2)	45	Smoking status: (i) Smoker <10 cig/d; (ii) Smoker ≥10 cig/d; (iii) Nonsmoker	SSQ	Absent
McDevitt et al., 2014	(3500–5400 MASL); Thorong-La, Annapurna, Nepal; Trekkers	Cross-sectional	332	Smoking status: (i) Smoker; (ii) Nonsmoker	LLS ≥ 3; LLS ≥ 5; ESQ > 0.7	Present
Mairer et al., 2009	2200–3500 MASL Eastern Alps; Mountaineers	Cross-sectional	431	Smoking status: (i) Smoker; (ii) Nonsmoker	LLS ≥ 4	Absent
Mairer et al., 2010	3454-4049 MASL in Eastern Alps; Mountaineers	Cross-sectional	79	Smoking status: (i) Smoker; (ii) Nonsmoker	LLS ≥ 4	Absent
Mairer et al., 2010	3817-4808 MASL in Western Alps; Mountaineers	Cross-sectional	83	Smoking status: (i) Smoker; (ii) Nonsmoker	LLS ≥ 4	Absent
Schneider et al., 2001	4559 MASL; Capanna Margherita, Italy; Mountaineers in 1996 and 1999	Cross-sectional	440	Smoking status: (i) No smoking; (ii) Smoking	ESQ > 0.7	Present
Schneider et al., 2001	4559 MASL; Capanna Margherita, Italy; Mountaineers in 2000	Cross-sectional	387	Smoking status: (i) No smoking; (ii) Smoking	ESQ > 0.7	Present

SSQ: study-specific questionnaire; AMS: acute mountain sickness; ESQ: environmental symptom questionnaire; NS: not stated; LLS: Lake Louise Score.