Discussion

This study examined the frequency of water exposure, exposure to water for recreation and risk-taking behaviours while swimming or playing in water for young children in rural Bangladesh. It compared these in children who had learned to swim in the SwimSafe programme with similar children who had learned swimming naturally. Almost all water exposure for children in both groups came from bathing (hygiene-related). Less than 1% of either cohort swam or played in the water during the 48 h period studied. There were no differences in overall water exposure, recreational water exposure for playing or swimming, and the high-risk behaviour of playing or swimming alone.

The study shows recreational water exposure is a very small fraction of all children's daily water exposure in the study population. While commonly thought that children in rural areas of Bangladesh spend large amounts of time playing, most children 4 years and older have responsibilities for domestic chores, assisting in the fields, helping with animals, supervising siblings and often enrolling in school. As a result, they do not have a large amount of unstructured time to play. The survey results are consistent with this, showing water entry for recreation is not a daily event for most, even when the weather is warm and ponds and other water bodies are full.

The need to enter water for essential daily activities has meant that the majority of children in Bangladesh learn swimming informally, often from a young age. Thus, Bangladeshi children do have water exposure through playing and swimming, although at much lower rates than water exposure for bathing. Learning swimming skills informally is a cultural norm for rural children. An anthropological study on natural acquisition of swimming ability in rural Bangladesh showed it is a structured process that begins in infancy and continues through early childhood. Some children are able to swim from 3 years of age.9 The BHIS national survey found that a large majority of children, both rural and urban, have naturally acquired swimming ability by the end of childhood.2 Over three-quarters of children in Bangladesh learn to swim by age 17 and engage in recreational water play or swimming throughout the length of childhood.

The study examined whether recreational water exposure that does occur does so with increased risk. Solitary, unaccompanied play or swimming in water presents such an increased risk. A child who gets into trouble while alone has no one to provide help to prevent them from drowning. One goal of SwimSafe was to educate caretakers and children to the risk of this practice and reduce it. This rarely occurred for either group. Future research will be needed to see whether this is due to the limited sample size.

The methodology employed in this study to examine risk and water exposure should be considered in the context of the limited but growing international literature on risk exposure measures for drowning.10 The alternative measure of time in water, for example, relies on observational methods that may be suitable for well-resourced studies, particularly in high-income settings where fatal drowning rates are low. In such settings, it is useful to precisely discriminate high-risk groups as they may vary greatly from the overall population risk. In LMICs, especially in rural settings, proximity to water is universal across virtually all population subgroups. In such high-exposure environments with their subsequent high rates of drowning and paucity of public health resources, the overall population risk is suitable to inform policy and develop appropriate prevention measures.

Observational methods were not practical in this study. The self-reported nature of the data from young children is a limitation. Children were asked to report the main reason for water entry, and it is possible that multiple behaviours occurred for each entry. Since recreational water exposure infrequently involved the caretaker, it was not possible to validate the self-report of the children. Similarly, the length of each recreational exposure was unable to be determined as young children do not have watches and the study involved self-report and not observation by others. Finally, the self-reported swimming ability for the naturally acquired swimming cohort was not tested through observation. The reporting methodology has been standardised.11 It has been validated by comparison of stated swimming ability and measured swimming ability in the same study populations (unpublished data, summary available on request).

An important limitation in this study is power. It is likely that if increased water exposure or risk-taking while in the water occurs as a result of learning to swim, it only occurs at low levels. Indirect evidence for this can be seen in the nested case–control study in the BHIS national survey. The study showed lack of swimming ability was associated with higher risk of drowning (OR=4.5, 95% CI 1.25 to 19.4).2 The lower drowning risk in children able to swim suggests learning to swim does not lead to large increases in high-risk behaviours that result in drowning. If such behaviours were frequent, drowning rates would be higher among children with swimming ability, reflecting the increased risk. At the level of discrimination in this study with pooled samples of 7046 children at two different points in the swimming season, children learning to swim through SwimSafe do not appear to have increased exposure to water or high-risk behaviours when in the water. However, that does not exclude these could occur in a small subgroup of children. Continued sampling among the expanded SwimSafe cohort and controls will be necessary to provide the levels of confidence needed when hundreds of thousands or millions of children are to be taught.

Another constraint is the short duration of recall. The 48 h recall period was chosen so that a child would be able to correctly recall detailed characteristics of each water exposure when guided by a trained interviewer. It is necessary to interview the child as many water exposures take place outside the knowledge of the caretaker. In fact, this study showed that many were solitary and caretaker interviews would not contain these. The short duration of recall provided detailed information on exposures that occurred, but may have reduced the likelihood of hearing about relatively infrequent exposures or risk-taking. While the study attempted to address this by having two different times of sampling, it is possible relatively infrequent behaviours would need more or longer sampling intervals before a high level of confidence could be reached.

This study does not address the question of whether children who have not learned to swim have greater water exposure or engage in risk behaviours such as playing alone in the water compared with children who have learned to swim. This is the subject of research in process and will be addressed in a future publication.

Importantly as well, this study only looked at rural children in Bangladesh. Children in other cultures in different LMICs may have different risk behaviour profiles. SwimSafe is being implemented in Thailand and Vietnam, and similar risk studies will be needed in these settings in order to address this question.

Despite these limitations, it appears that in Bangladesh participation in the SwimSafe programme does not result in an increased risk of water exposure or risk-taking when in the water for recreational purposes compared with children who learned swimming naturally. As scale increases further, continued vigilance with expanded surveys will be necessary to ensure that participation does not place children at increased risk as an unintended adverse consequence of the programme.