Prevalence and Correlates for Smoking among Persons Aged 25 Years or Older in Two Rural Districts of Zambia

IntroductionSmoking harms nearly all the organs of the body, being responsible for cardiovascular morbidity and mortality and causing the following cancers among others: lung cancer, cancer of the cervix, bladder cancer, cancer of the oesophagus, and stomach cancer (1). Smoking has been associated with infertility, preterm delivery, stillbirth, low birth weight and sudden infant death syndrome (1,2). Sub-Saharan Africa appears to differ from other regions of the world in having reached only the early stages of the cigarette epidemic (3). Pampel (4) using Demographic Health Survey data obtained between 2000 and 2006 reported the prevalence of smoking to vary from 8.0 to 27.3% among men across the sub-Saharan Africa, with the highest cigarette use among men in several nations of east/central Africa and Madagascar, lowest use in nations of west and central Africa, and medium use in nations of southern Africa. Meanwhile, the prevalence of smoking for women was much lower ranging from 0.1% to 5.9%. The prevalence for smoking was estimated at 15.6% for men and 0.5% for women in Zambia.Using the World Health Organization (WHO) STEPwise methodology, Zyaambo et al (5) estimated the prevalence of smoking among persons in Kitwe, Zambia, aged 25 years or older at 18.1% and 1.8% amongst males and females respectively with an overall prevalence of 8.7%. In a similar study, also set up in another urban setting, Lusaka, Zambia, Siziya et al (6) reported similar smoking rates of 17.5% among males and 1.5% among females with an overall prevalence of 6.8%. In the 2007 Zambia Demographic and Health Survey, the rate of use of tobacco products (smoking cigarettes or pipes) was higher in rural than urban areas; highest in persons with no education; and higher in persons in lowest or second wealth quintile (7). In this study, confounding factors and some other factors that have been observed to be associated with smoking in other studies were not considered in the analysis. No studies have been conducted in Zambia using the WHO STEPwise methodology in rural areas of Zambia. The objective of this study was to determine the prevalence and correlates for smoking among persons aged 25 years or older in two rural districts of Zambia.MethodsThe study was conducted in Kaoma and Kasama rural districts of Zambia with population sizes of 162,568 and 170,929, respectively (8). While tobacco is one of the 11 commonly grown crops in Kaoma (9), it is not one of the 13 commonly grown crops in Kasama (10). Crops that were grown in Kaoma in decreasing order were: maize, cassava, millet, sorghum, groundnuts, cotton, and mixed beans (9). Meanwhile, in decreasing order, maize, cassava, groundnuts, finger millet, sweet potatoes, beans, sugarcane, soya beans, sorghum, bambara nuts, sunflower, cow beans and rice were grown in Kasama district (10). Sample size and samplingA sample size of 7,660 was estimated using a Statcal program in EPI INFO version 6.04. The following parameters were used in the sample size calculation: a prevalence estimate of 50+5% (as no estimate existed), 8 provinces and a design effect of 2, and 80% response rate. Of the 7,660 participants, 843 were to be selected from Kasama and 766 from Kaoma. These sample sizes were increased to 1,196 in Kasama and 893 in Kaoma.A multi-stage sampling technique was used to select the participants. At the first stage of sampling, wards were randomly selected. In the second stage of sampling, standard enumeration areas (SEAs) proportionally selected to the ward size. Finally from the selected SEAs, households were systematically sampled. All individuals (male or female) aged 25 years or older in a selected household were eligible to participate in the study.Ethical considerationsEthical approval was granted by the University of Zambia Biomedical Research Ethics Committee. Permission to conduct the survey was obtained from the Ministry of Health [Zambia]. …