Beyond a symptom count:addressing the difficulties of measuring Functional Somatic Symptoms

Functional Somatic Symptoms (FSS) are a constellation of symptoms such as pain, fatigue, and dizziness, which are not explained by objectively measurable underlying pathology (also called medically unexplained). These symptoms are very heterogeneous, and therefore, difficult to assess. The overall aim of this thesis was to address three methodological issues in the assessment of FSS, namely: 1) The heterogeneity of FSS and the problems of using sum-scores, 2) the uncertainty concerning which symptoms are most relevant for FSS assessment, and 3) the ambiguity of the meaning of sum-scores for different subgroups. To address these issues, sophisticated psychometric methods from Item Response Theory were applied to three FSS questionnaires. The findings suggest that items related to weakness, heaviness in extremities, and nausea consistently provide accurate measurements about FSS severity. Moreover, it was found that some symptoms could be biased by sex, which means that these items may be more accurate at measuring FSS severity in either males or females. Joint pain was found not to be very informative when measuring FSS in older adults. Finally, we found that participants did not tend to cluster in subgroups based on their symptoms (e.g., gastrointestinal or musculoskeletal), but based on their overall severity of symptoms. This means that the severity of FSS symptoms could be more important for identifying and classifying individuals than the combination of symptoms. These results can contribute to the improvement of measurement tools for assessing FSS

Associated factors for mortality in a COVID-19 colombian cohort : is the third wave relevant when Mu variant was predominant epidemiologically?

Q1Q1Pacientes con COVID-19Objectives: To evaluate the association between Colombia's third wave when the Mu variant was predominant epidemiologically (until 75%) in Colombia and COVID-19 all-cause in-hospital mortality. Methods: In this retrospective cohort, we included hospitalized patients ≥18 years with SARS-CoV-2 infection between March 2020 to September 2021 in ten hospitals from three cities in Colombia. Description analysis, survival, and multivariate Cox regression analyses were performed to evaluate the association between the third epidemic wave and in-hospital mortality. Results: A total of 25,371 patients were included. The age-stratified time-to-mortality curves showed differences according to epidemic waves in patients ≥75 years (log-rank test p = 0.012). In the multivariate Cox analysis, the third wave was not associated with increased mortality relative to the first wave (aHR 0.95; 95%CI 0.84–1.08), but there was an interaction between age ≥75 years and the third wave finding a lower HR for mortality (aHR 0.56, 95%CI 0.36–0.86). Conclusions: We did not find an increase in in-hospital mortality during the third epidemic wave in which the Mu variant was predominant in Colombia. The reduced hazard in mortality in patients ≥75 years hospitalized in the third wave could be explained by the high coverage of SARS-CoV-2 vaccination in this population and patients with underlying conditions.https://orcid.org/0000-0003-1833-1599https://orcid.org/0000-0001-5363-5729https://orcid.org/0000-0001-6964-2229https://orcid.org/0000-0003-3975-2835https://orcid.org/0000-0001-9441-4375Revista Internacional - IndexadaA1N