METHODS: A randomised controlled experiment was conducted from 29 April to 7 June 2021, which coincided with the early phases of the national vaccination programme when vaccine uptake data were largely unavailable. 5784 Malaysians were randomly allocated into 14 experimental arms and exposed to one or two messages that promoted COVID-19 vaccination. Interventional messages were applied alone or in combination and compared against a control message. Outcome measures were assessed as intent to both take the vaccine and recommend it to healthy adults, the elderly, and people with pre-existing health conditions, before and after message exposure. Changes in intent were modelled and we estimated the average marginal effects based on changes in the predicted probability of responding with a positive intent for each of the four outcomes.
RESULTS: We found that persuasive communication via several of the experimented messages improved recommendation intentions to people with pre-existing health conditions, with improvements ranging from 4 to 8 percentage points. In contrast, none of the messages neither significantly improved vaccination intentions, nor recommendations to healthy adults and the elderly. Instead, we found evidence suggestive of backfiring among certain outcomes with messages using negative attribute frames, risky choice frames, and priming descriptive norms.
CONCLUSION: Message frames that briefly communicate verbatim facts and stimulate rational thinking regarding vaccine safety may be ineffective at positively influencing vaccine-hesitant individuals. Messages intended to promote recommendations of novel health interventions to people with pre-existing health conditions should incorporate safety dimensions.
TRIAL REGISTRATION NUMBER: NCT05244356.
MATERIALS AND METHODS: This was a retrospective descriptive study. We identified 1041 patients (810 Chinese, 139 Malays, 92 Indians) without previous history of cardiovascular disease who underwent cardiac computed tomography for atypical chest pain evaluation. A cardiologist, who was blinded to the patients' clinical demographics, reviewed all scans. We retrospectively analysed all their case records.
RESULTS: Overall, Malays were most likely to be active smokers (P = 0.02), Indians had the highest prevalence of diabetes mellitus (P = 0.01) and Chinese had the highest mean age (P <0.0001). The overall prevalence of patients with non-calcified plaques as the only manifestation of sub-clinical coronary artery disease was 2.1%. There was no significant difference in the prevalence of CAC, mean CAC score or prevalence of non-calcified plaques among the 3 ethnic groups. Active smoking, age and hypertension were independent predictors of CAC. Non-calcified plaques were positively associated with male gender, age, dyslipidaemia and diabetes mellitus.
CONCLUSION: The higher MI rates in Malays and Indians in Singapore cannot be explained by any difference in CAC or non-calcified plaque. More research with prospective follow-up of larger patient populations is necessary to establish if ethnic-specific calibration of CAC measures is needed to adjust for differences among ethnic groups.
CASE PRESENTATION: We describe a 3-year-old Malay boy who presented with simple febrile seizure and had no neurological deficit, however, he was found to have microangiopathic hemolytic anemia, thrombocytopenia, and elevated serum lactate dehydrogenase. An ADAMTS13 assay results showed zero activities (0%), and markedly high level of ADAMTS13 inhibitor (93.15 U/mL) confirming the diagnosis of secondary thrombotic thrombocytopenia purpura. He received fresh frozen plasma infusions for 3 days and subsequently his platelet levels normalized. Serial ADAMTS13 assay results showed improvement. He was also given a short course of prednisolone after which the ADAMTS13 activity normalized (> 114%) at the end of prednisolone course.
CONCLUSIONS: At presentation, acquired thrombotic thrombocytopenia purpura in a very young child is commonly misdiagnosed as other conditions like idiopathic thrombocytopenic purpura, Evans syndrome, atypical hemolytic-uremic syndrome, or malignancy. ADAMTS13 assay should be performed early when thrombotic thrombocytopenia purpura is suspected as this condition is associated with dire consequences.