The development, design, recruitment, conduct and you may results of new moms and dad PCV investigations and that nested studies was basically conveyed towards the social as a consequence of local community sensitisation group meetings kept from the Projahnmo research group lumen consortium when you look at the Sylhet, Bangladesh.
Participant qualities
From , the CHWs visited 2098 households and attempted SpO2 measurements on 2042 children (figure 2). Overall, 20 children with low-quality SpO2 measurements were excluded at the analysis stage. For priple 1, a total of 552 children were additionally omitted due to abnormal heart rates. For analytical sample 2, 157 children were excluded based on reference heart ranges. Among the 1470 children analysed for analytical sample 1, the mean age was 18.6 months (SD, 9.5) (table 1). Average age and the proportion of participants who were female were similar across the three analytical samples.
Supplemental topic
After stratifying measurements into three age strata, 3–11 months, 12–23 months and 24–35 months, we found children 3–11 months old in priple 1 to have a median SpO2 of 97%, compared with 98% for each of the two older age strata (p=0.038; table 1 and figure 3). We observed similar findings in analytical samples 2 and 3 (table 1 and online supplemental figures 1 and 2). When regressing SpO2 on age in months, adjusted for sex, we found that for every 1 month increase in age the SpO2 increased by 0.01% (95% CI 0.001% to 0.02%, p=0.030) in analytical sample 1 (online supplemental figure 3). We did not observe any difference in the SpO2 distribution after stratifying by child sex (p=0.959).
Wellness system implications regarding differing SpO2 thresholds
To examine possible consequences on the health system of a SpO2 threshold for defining hypoxaemia derived from well children we report the probability of a false positive measurement in table 2 from each analytical sample at differing thresholds. If applying a < 92% threshold, for example, (5.1%) well children included in analytical sample 1 would be incorrectly recommended for referral or hospitalisation. SpO2 thresholds at ?90%, < 91% and < 93% would incorrectly identify 13 (0.8%), 40 (2.7%) and 117 (7.9%) of the 1470 children in analytical sample 1 for hospitalisation, respectively.
Dialogue
We derived possible SpO2 thresholds for hypoxaemia from the 2.5th, 5th and 10th percentile cutoffs of well children in rural Bangladesh and estimated the probability of false positive measurements assuming a revised threshold was adopted into care. The SpO2 threshold is critical as it triggers a cascade of potentially life or death healthcare decisions and understanding the probability of a false positive SpO2 measurement for hypoxaemia permits health policy-makers to decide how best to balance mortality risk with anticipated hospitalisation volumes.
There are three key findings from this research. First, cutoffs for hypoxaemia from the 2.5th, 5th and 10th percentile are all higher than the current WHO-defined <90% threshold and we did not find any well children below the SpO2 <90% threshold. Thus, if any of these cutoffs for hypoxaemia are adopted then measuring the SpO2 earlier in clinical care pathways when healthier children may be over-represented could increase false positive measurements. This has important implications in health systems with limited resources and potential challenges coping with a higher volume of patient referrals. These results, coupled with findings from Malawi that children with LRI and a SpO2 between 90% and 92% are at elevated mortality risk, suggest that the current referral threshold of SpO2 <90% minimises false positives at the expense of false negatives.6–8 In order to ensure minimal misclassification of well children as hypoxaemic, we recommend care algorithms incorporating a hypoxaemia threshold at SpO2 levels higher than <90% also consider the child's clinical status when deciding whether to refer and hospitalise. Second, we found that the SpO2 distribution differs by age. Age may, therefore, need to be considered when establishing a SpO2 threshold for hypoxaemia. Third, these data show that a 2.5th percentile SpO2 threshold in all analytical samples and nearly all age categories is at a 91% cut-off. When compared with the currently recommended <90% WHO cut-off (or < 89% inclusive), this <91% threshold (or < 91% inclusive) is at the margin of the 2% accuracy range for most pulse oximeters.19 As a result, if a higher SpO2 threshold were to be considered the 5th or 10th percentile threshold may be more suitable when considering inherent device accuracy limitations. Overall, future analyses that include unwell children should consider prioritising SpO2 thresholds outside of the device accuracy range, such as the 5th or 10th percentile in this analysis, as well as whether the statistical relationship between age and SpO2 distribution has clinical significance.
