Walker et al.’s color of bile vomiting in intestinal obstruction in the newborn: questionnaire study sought to determine the color that various observers thought indicated that the newborn’s vomit contained bile. The researchers maintain that the green color in newborns’ vomit indicated bile presence to establish the objective. In addition to that, the researchers argued that the green color in the vomit pointed towards intestinal obstruction. Walker et al.’s color of bile vomiting in intestinal obstruction in the newborn: questionnaire study, links green bile vomiting to intestinal obstruction.
The hypothesis exploring bile vomiting by associating it with green is appropriate for the study primarily because it sought to exclude other mechanical obstructions that would present another coloring such as yellow (Walker et al., 2006). Moreover, the hypothesis addresses a significant clinical issue critical to decision-makers in considering new evidence. However, excluding mechanical obstruction was based on yellow vomit, although they were determined to have an intestinal obstruction. Therefore, yellow vomit in infants had the potential to demonstrate intestinal obstruction. The hypothesis presents issues in pointing out the green vomit as being associated with bile vomiting when the yellow vomit is similarly attributed to intestinal obstruction.
The study researchers opted for a convenience sampling technique in selecting the setting for the study because of the study subjects involved (infants). Level III special care infant unit and postnatal ward in a university teaching hospital got appropriately selected for the study. Moreover, toddlers and mother groups in Glasgow were conveniently sampled for the study. Similarly, the researchers selected 29 nurses on the infant unit and 41 mothers of infants purposively to realize the study’s objective (Walker et al., 2006). The sampling technique used sufficiently addressed the purpose of the study given the participants, and the study location allows for interaction with the infants. However, the study results might not be generalizable due to the setting protecting the study subjects from various factors influencing the outcome, such as access to health information. In addition to that, the sampling method used narrows the results of the research because they are difficult to extrapolate. Therefore, replication of the study is equally challenged by using the convenience sampling method.
The researchers used various groups, including 29 nurses on the infant unit, 47 general practitioners, and 41 mothers in Glasgow (Walker et al., 2006). These participants were selected given the study population was comprised of infants. Therefore, the subjects were appropriate for the study having immediate interactions with the infants. The subjects chosen were considered purposively for the study by ensuring they were literate and could fill out the questionnaire. Recruitment bias was handled through the convenient method of selecting the study participants. The study excluded those who have limited interactions with babies or infants. Moreover, the study utilizes subjects in real-life circumstances for observational purposes. This approach provides credibility to the findings primarily because the participants have access to the infants without a time limitation. Similarly, they have access to vital information about the significance of the study outcomes.
The study design employed by the researchers involved the use of questionnaires to capture the participants’ responses in a bid to determine the color of infant vomiting. According to the researchers, bile vomiting is associated with intestinal obstruction. Therefore, the authors sought to determine the color of vomit whereby eight shades ranging from pale yellow to dark green were used (Walker et al., 2006). Whereas the study involved eight colors in determining the bile presence with a range of pale to dark, the authors pointed out that green was the only color associated with bile vomiting. This conclusion makes an assumption of the pale green and dark green colors by combining them. The authors ultimately considered only two colors out of the eight colors represented on the questionnaire. The study design used fails to measure the outcome of the study adequately. While green and yellow are primary colors used to depict bile vomiting, both colors are associated with intestinal obstruction. However, the authors are inclined towards using the green vomit to indicate bile vomiting while acknowledging that a proportion of infants with intestinal obstruction might be characterized by yellow vomit.
The sample size used by the researchers was statistically insignificant because of the small number of subjects. Having such a small sample size increases the chance by decreasing the reliability of the findings. Furthermore, having such a sample size makes the study prone to an alpha error where a conclusion might indicate significance when it is contributed by sampling error. Moreover, postnatal ward midwives determined green color more frequently than general practitioners, but the difference was considered insignificant (Walker et al., 2006). Such interpretation demonstrates a beta error where the conclusion portrays that the results have no effect. The beta error could get eliminated by increasing the sample size. For instance, increasing the number of postnatal ward midwives would have made their results significant.
Apart from the sample size issues, the research lacked a follow-up period to ascertain the authenticity of the findings. For example, a study group involving mothers depended upon memory to determine the color, thus leading to high chances of recall bias. By having adequate time to undertake follow-up of the results, the authors would increase the significance/replicability of the findings. Having a large sample size does not address the recall bias; therefore, the research fails in addressing the underlying systematic bias.
Walker et al. highlight the discussion of the study by pointing out the association between bile in the vomit and surgical conditions such as intestinal obstruction in infants (Walker et al., 2006). The authors appropriately argue that vomiting is an early sign of surgical conditions in babies. By associating the presence of bile in an infant’s vomit with intestinal obstructions, the authors can explore the significance of bile vomiting to surgical conditions. Bile vomiting in infants is thus discussed as an indication of intestinal obstruction. Moreover, the article highlights parents associating vomit comprising non-food gastric residue to bile. Whereas Walker et al. highlight this significant point, they fail to capture it in the study fully. However, they explain that their responses were not surprising because of such a notion. Furthermore, the study fails to discuss the importance of the infant’s medical history when administering the questionnaire to parents. The infant’s medical history can increase the credibility of the findings by lowering the recall bias.
Walker et al. link infants’ bile vomiting to intestinal obstruction. The authors demonstrate how the color of the infant’s vomit could be used as an indicator of surgical conditions, including intestinal obstruction. Moreover, whereas the discussion indicates that the results from specialist nurses were surprising, the study does not emphasize the ability of yellow color associated with intestinal obstruction. Specialist nurses indicated that yellow was the right match for bile vomiting. The authors fail to discuss this finding or examine its impact on the outcomes. An indication that yellow vomit could indicate intestinal obstruction is not discussed but merely suggested for further study. However, the green vomit was associated with surgical conditions in infants, thus calling for immediate referral. Therefore, the researchers measured the outcome by associating green vomit with intestinal obstruction, providing appropriate information to decision-makers, including parents and specialist nurses.
Walker, G.M., Neilson, A., Young, D., & Raine, P.A.M. (2006). Color of bile vomiting in intestinal obstruction in the newborn: questionnaire study. British Medical Journal, 332(1363), 1-3.