Prevalence of obstructive lung disease in an African country using definitions from different international guidelines: a community based cross-sectional survey

BACKGROUND: Obstructive lung disease (OLD), a major global public health problem, has been less investigated in African countries. We assessed the prevalence and determinants of OLD in Yaounde (the capital city of Cameroon), using internationally agreed definitions. METHODS: Participants were adults (age >19 years) screened during a community-based survey between December 2013 and April 2014. Air flow limitation (AFL) was based on a pre-bronchodilator forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) below the lower limit of normal (LLN, AFL–LLN). Chronic obstructive pulmonary disease (COPD) was based on post-bronchodilator FEV1/FVC ratio < LLN (COPD–LLN). RESULTS: Of the 1287 subjects included, 51.9 % were female, 9.3 % were current smokers and their mean age was 34.4 ± 12.8 years. Forty-nine (3.8 %, 95 % CI 2.8–4.9 %) participants had AFL–LLN. Thirty-one subjects had COPD–LLN; giving a prevalence of COPD–LLN of (2.4 %, 95 % CI 1.6–3.3 %). In multivariable analysis, male gender (AOR 2.42; 95 % CI 1.12–5.20) and lifetime wheezing (AOR 2.88; 95 % CI 1.06–7.81) were the determinants of COPD-LLN. Otherwise, male sex (AOR 1.93, 95 % CI 1.00–3.73), age 40–59 years (AOR 1.99, 95 % CI 1.04–3.81) and lifetime wheezing (AOR 2.65, 95 % CI 1.13–6.20) remained as independent determinants of AFL–LLN. CONCLUSIONS: Obstructive lung disease based on more accurate definitions was relatively infrequent in this population. It is important to sensitize the medical staff and the general public about this condition which should be actively investigated in individuals aged 40 years and above.