Journal of Statistics on Health Decision

The impact of vaccination on transmission and death by COVID-19: an observational study in Portugal’s biggest primary care cluster

Sofia Tedim — 2022-12-22

Vaccines are a key tool to manage the COVID-19 pandemic by preventing infection, hospitalization, severe disease, or death. In Portugal, information on vaccine effectiveness in real-life settings is still limited. Therefore, the main goal of this study is to evaluate the association between vaccination against COVID-19 and mortality and transmissibility in the population of the biggest Primary Care Cluster in Portugal, ACES Baixo Vouga (ACES BV).

A retrospective, observational study including all reported cases of COVID-19 in ACES BV between December 2020 and September 2021 was conducted (N=18,415). Anonymized data on demographic, clinical, epidemiological characteristics and outcomes of interest of the COVID-19 confirmed cases were collected. To model vaccination’s association with death, a logistic regression analysis was performed. To estimate the effect of vaccination on the number of secondary cases, a zero-inflated negative binomial model was used.

Of 18,415 confirmed cases included in this study, 1,981 (10.8%) were vaccinated. A complete vaccination scheme against COVID-19 (OR=0.22, CI95 0.09-0.47) and female sex (OR=0.42, CI95 0.30-0.57) protected against death, while age (OR=1.12, CI95 1.10-1.13), comorbidities (OR=4.14, CI95 2.27- 8.34) and the presence of symptoms (OR=1.72, CI95 2.27-8.34) increased the odds of death. A complete vaccination scheme (RR 0.63, CI95 0.49–0.81) decreased the risk for the number of secondary cases in the model without outliers.

It is vital to monitor the vaccination effects in the real world and to better understand the characteristics of COVID-19 vaccine-induced immunity.

Fonseca anamnestic index for screening Temporomandibular Disorders - reliability to discriminate muscular from intra-articular disorders.

Ricardo Miguel Vieira de São João, PhD — 2022-12-22

Background/ Objective: Fonseca anamnestic index (FAI) is a simple and quick survey used for screening the presence and severity of Temporomandibular Disorders (TMD). The presented study aimed to screen the FAI accuracy to discriminate different types of TMD: intra-articular (AD), Masticatory Muscular Disorder (MMD), or the presence of both typologies.

Methods: The existence of a pattern in the FAI based on the frequency of answers was evaluated and supported by other variables: sex, age, medical diagnosis and Visual Analog Scale of health-related quality of Life (VASLife). The non-parametric Chi-square test () or Fisher's exact test were used to assess the existence of associations between these variables. In the pairs of variables where such association was identified, its intensity was measured by Cramér's V Coefficient. The prediction if FAI could be a good decision tool for distinguish the type of TMD was assessed through logistic regression models (ordinal and multinomial).

Results: The higher FAI score was associated with questions related with temporomandibular joint (TMJ) pain, TMJ clicks and person anxiety. Severe cases classified by FAI are correlated with typology of Both (AD+MMD). Moreover, the female patients presented more moderate and severe cases in FAI and also correlated with the presence of AD+MMD. The logistic model showed low accuracy to distinguish the TMD typology (~70%).

Conclusion: FAI is a good initial methodology in TMD diagnosis, however integrated in a logistic regression model for distinguish the typology of TMD has proved to be insufficient. It is expected that the combination of this survey with other outcomes will make the model more accurate.

Effects of temperature and mobility on COVID-19 incidence

Vanusa Rocha — 2022-12-22

Background/Objective: The purpose of this study was to evaluate the association between COVID-19 weekly case numbers with the trend, average temperature (AT) and mobility (MOB) at the national level and by regions, in Portugal.

Methods: We compiled a weekly dataset including COVID-19 case numbers, average temperature and mobility during the period of March 23, 2020, to August 30, 2022. Negative binomial regression was fitted to estimate the effect of covariates on the COVID-19 case numbers.

Results: We observed a significant increasing effect over time in most regions, negative temperature effect, in all regions, and a positive mobility effect, in most regions, on the number of cases using a two-week lag.

Conclusion: Increased mobility and low temperatures were associated with higher numbers of cases of COVID-19 infection.

Meta-analysis of Chemical exposure and increased risk of hematologic malignancies.

Gisela Ferreira — 2022-12-30

Background: Exposure to environmental risk factors may be associated with the development of hematologic malignancies, as pointed by evidence in the literature. Despite this, most studies refer to a specific risk factor or disease.

Objective: To assess this issue globally, in this study we performed a meta-analysis.

Methods: A searched PubMed database was done in 2020 and a selection of 35 case-control and cohort studies published between 1990 and 2020 was done.

Results: Was observed a significant adverse association between exposure to organic solvents such as benzene and incidence of myeloid malignancies. For agricultural chemicals (pesticides, herbicides, insecticides), an adverse association was found for both lymphoid and myeloid malignancies.

Conclusions: The results suggest that activities in chemical industries or agriculture pose greater risk and should be closely monitored. Prospective occupational surveys are needed to identify exposure–response relationships and clarify disease mechanisms.