Validity of prognostic models of critical COVID-19 is variable. A systematic review with external validation.

OBJECTIVES: To identify prognostic models which estimate the risk of critical COVID-19 in hospitalized patients and to assess their validation properties. STUDY DESIGN AND SETTING: We conducted a systematic review in Medline (up to January 2021) of studies developing or updating a model that estimated the risk of critical COVID-19, defined as death, admission to intensive care unit, and/or use of mechanical ventilation during admission. Models were validated in two datasets with different backgrounds (HM [private Spanish hospital network], n = 1,753, and ICS [public Catalan health system], n = 1,104), by assessing discrimination (area under the curve [AUC]) and calibration (plots). RESULTS: We validated 18 prognostic models. Discrimination was good in nine of them (AUCs ≥ 80%) and higher in those predicting mortality (AUCs 65%-87%) than those predicting intensive care unit admission or a composite outcome (AUCs 53%-78%). Calibration was poor in all models providing outcome's probabilities and good in four models providing a point-based score. These four models used mortality as outcome and included age, oxygen saturation, and C-reactive protein among their predictors. CONCLUSION: The validity of models predicting critical COVID-19 by using only routinely collected predictors is variable. Four models showed good discrimination and calibration when externally validated and are recommended for their use.

Validation of a Parent-Reported Physical Activity Questionnaire by Accelerometry in European Children Aged from 6 to 12 Years Old.

Validated physical activity (PA) questionnaires are crucial for collecting information in large epidemiological studies during childhood. Thus, this study analyzed the validity of a parent-reported PA questionnaire based on the Children's Leisure Activities Study Survey by accelerometry in European children aged from 6 to 12 years old. We used data from 230 children of the Human Early-Life Exposome and Infancia y Medio Ambiente projects. Mean differences between moderate-to-vigorous PA (MVPA) reported by the questionnaire and the accelerometer were calculated (min/day), and its associated factors were explored by multiple robust linear regression. The agreement between methods was examined using a Bland−Altman plot. The concurrent validity of assessing MVPA was analyzed by cohort-adjusted Spearman's partial correlations. ROC curve analysis was also used to explore the questionnaire's capability to identify active children based on the World Health Organization guidelines. A moderate correlation was found between parent-reported and accelerometer MVPA (rho = 0.41, p < 0.001). The child's sex (girl) was statistically associated with the mean MVPA difference between methods. However, this questionnaire accurately identified physically active children (area under the curve = 83.8% and 82.7% for boys and girls, cut-points = 68.6 and 45.4 min/day in MVPA, respectively). Consequently, this questionnaire is suitable for classifying active children in order to monitor public health interventions regarding PA.

Prospective Associations between Maternal and Child Diet Quality and Sedentary Behaviors.

As the most likely primary caregivers, mothers are an integral part of children's social influence and are therefore greatly involved in shaping their children's behaviors. The objectives were to determine the prospective associations between maternal and child diet quality and sedentary behaviors. This study, within the framework of a community-based intervention study, included 1130 children aged 8-10 years and their mothers. The study was carried out during two academic years (2012/2014) with a mean follow-up of 15 months. Exposure and outcome variables were measured at baseline and follow-up, respectively. Diet quality was assessed by the KIDMED questionnaire and the short Diet Quality Screener, respectively. Sedentary behaviors were determined by standardized questions of sedentary behaviors. Maternal consumption of fruits, vegetables, fish, legumes, pasta/rice, dairy products, nuts and baked goods were positively associated (p < 0.05) with the corresponding child behavior. Multiple linear regression models adjusted for sex, age, maternal education and intervention group revealed significant cross-sectional (p < 0.005) and prospective (p < 0.01) associations between maternal and child overall diet quality and sedentary behaviors. Maternal diet quality and sedentary behaviors were predictive for these lifestyle behaviors in children.

Anthropometric Variables as Mediators of the Association of Changes in Diet and Physical Activity With Inflammatory Profile.

BACKGROUND: Mechanisms underlying the associations of high levels of physical activity (PA) and adherence to the Mediterranean diet (MedDiet) with a better inflammatory profile remain unclear. Our objective was to assess the mediating role of changes in body mass index (BMI) and waist circumference (WC), as markers of body fat in the association of changes in PA and adherence to the MedDiet, with changes in the inflammatory profile. METHOD: This study included 489 adults, aged 55-75 years, from the PREDIMED-Plus multicenter lifestyle intervention trial. An inflammatory score was calculated, based on 8 blood biomarkers: high-sensitivity C-reactive protein, interleukin 6, interleukin 8, interleukin 18, monocyte chemo-attractant protein-1, C-peptide, leptin, and regulated on activation, normal T-cell-expressed and secreted chemokine. Biomarkers, levels of PA, score of MedDiet adherence, BMI, and WC were measured at baseline and at 1-year follow-up. Linear regression models were fitted according to the Baron and Kenny framework for mediation analysis. RESULTS: Changes in BMI and WC mediated the association of both changes in PA and changes in the MedDiet adherence with the inflammatory score. Body mass index mediated 26% of the association of changes in total PA with the inflammatory profile, and 27% of the association of changes in the MedDiet, while WC mediated 13% and 12% of these associations, respectively. CONCLUSION: In older adults at high cardiovascular risk, increasing PA levels and adherence to a MedDiet during 1 year were associated with a lower inflammatory score, which was partly mediated by a reduction in body fat. CLINICAL TRIALS REGISTRATION NUMBER: International Standard Randomized Controlled Trial Number: ISRCTN89898870; registration date July 24, 2014, retrospectively registered.

Prospective Association of Maternal Educational Level with Child's Physical Activity, Screen Time, and Diet Quality.

Evidence has identified unhealthy lifestyle behaviors as the main contributors to obesity in children, so it is essential to identify factors that could influence children's lifestyles. The objective of the present study was to analyze the association of baseline maternal educational level with child's physical activity, screen time, and dietary habits at follow-up. This community-based cohort study was carried out between 2012 and 2014 and included 1405 children aged 8 to 10 years old. Maternal educational level was used as an indicator of child's socioeconomic status. Physical activity, screen time, and dietary habits were assessed by validated questionnaires. The odds of having commercially baked goods for breakfast [OR 1.47 (95% CI 1.03 to 2.10)], going more than once a week to a fast-food restaurant [OR 1.64 (95% CI 1.20 to 2.26)], and taking sweets and candys several times a day [OR 3.23 (95% CI 2.14 to 4.87) were significantly higher among children whose mothers had a lower educational level compared to their peers whose mothers had a higher level. These associations held for taking sweets and candy several times a day after additional adjustment for the corresponding dietary behavior at baseline. Maternal educational level was inversely associated (p < 0.001) with child's screen time at follow up and being in the lowest maternal educational category was associated with an increased odds of surpassing the maximum recommended time of screen time of 120 min per day (OR (95% CI) 1.43 (1.07 to 1.90), p = 0.016). Maternal education is a predictor for unhealthy dietary habits and high screen time in children.

Multiple approaches to associations of physical activity and adherence to the Mediterranean diet with all-cause mortality in older adults: the PREvención con DIeta MEDiterránea study.

PURPOSE: Although evidence indicates that both physical activity and adherence to the Mediterranean diet (MedDiet) reduce the risk of all-cause mortality, a little is known about optimal intensities of physical activity and their combined effect with MedDiet in older adults. We assessed the separate and combined associations of leisure-time physical activity (LTPA) and MedDiet adherence with all-cause mortality. METHODS: We prospectively studied 7356 older adults (67 ± 6.2 years) at high vascular risk from the PREvención con DIeta MEDiterránea study. At baseline and yearly thereafter, adherence to the MedDiet and LTPA were measured using validated questionnaires. RESULTS: After 6.8 years of follow-up, we documented 498 deaths. Adherence to the MedDiet and total, light, and moderate-to-vigorous LTPA were inversely associated with all-cause mortality (p < 0.01 for all) in multiple adjusted Cox regression models. The adjusted hazard of all-cause mortality was 73% lower (hazard ratio 0.27, 95% confidence interval 0.19-0.38, p < 0.001) for the combined category of highest adherence to the MedDiet (3rd tertile) and highest total LTPA (3rd tertile) compared to lowest adherence to the MedDiet (1st tertile) and lowest total LTPA (1st tertile). Reductions in mortality risk did not meaningfully differ between total, light intensity, and moderate-to-vigorous LTPA. CONCLUSIONS: We found that higher levels of LTPA, regardless of intensity (total, light and moderate-to-vigorous), and greater adherence to the MedDiet were associated separately and jointly with lower all-cause mortality. The finding that light LTPA was inversely associated with mortality is relevant because this level of intensity is a feasible option for older adults.

Effectiveness of the physical activity intervention program in the PREDIMED-Plus study: a randomized controlled trial.

BACKGROUND: The development and implementation of effective physical activity (PA) intervention programs is challenging, particularly in older adults. After the first year of the intervention program used in the ongoing PREvención con DIeta MEDiterránea (PREDIMED)-Plus trial, we assessed the initial effectiveness of the PA component. METHODS: PREDIMED-Plus is an ongoing randomized clinical trial including 6874 participants randomized to an intensive weight-loss lifestyle intervention based on an energy-restricted Mediterranean diet (MedDiet), physical activity promotion and behavioral support and to a control group using MedDiet recommendations but without calorie restriction or PA advice. Body mass index (BMI) and waist circumference (WC) are measured by standard clinical protocols. Duration and intensity of PA is self-reported using the validated REGICOR Short Physical Activity Questionnaire. The primary endpoint of the PREDIMED-Plus trial is a combined cardiovascular outcome: myocardial infarction (acute coronary syndromes with positive troponin test), stroke, or cardiovascular mortality. The present study involved secondary analysis of PA data (n = 6059; mean age 65 ± 4.9 years) with one-year changes in total, light, and moderate-to-vigorous PA within and between intervention groups as the outcome. Generalized estimating equation models were fitted to evaluate time trends of PA, BMI, and WC within groups and differences between intervention and control groups. RESULTS: After 12 months, average daily MVPA increased by 27.2 (95%CI 5.7;48.7) METs-min/day and 123.1 (95%CI 109.7-136.6) METs-min/day in the control and intervention groups, respectively. Total-PA, light-PA, and MVPA increased significantly (p < 0.01) in both groups. A significant (p < 0.001) time*intervention group interaction was found for Total-PA and MVPA, meaning the PA trajectory over time differed between the intervention and control groups. Age, sex, education level, and BMI did not moderate the effectiveness of the PA intervention. BMI and WC decreased significantly with increasing MVPA, compared with participants who reported no changes in MVPA. CONCLUSION: After one year of follow-up, the PREDIMED-Plus PA intervention has been effective in increasing daily PA in older adults. TRIAL REGISTRATION: Retrospectively registered at the International Standard Randomized Controlled Trial ( http://www.isrctn.com/ISRCTN89898870 ), registration date: 24 July 2014.

Association of physical activity with body mass index, waist circumference and incidence of obesity in older adults.

Background: There is limited, and inconsistent, data on the prospective association between physical activity and surrogate markers of adiposity in older adults. We aim to determine the prospective association of leisure time physical activity (LTPA) with body mass index (BMI), waist circumference (WC) and the incidence of obesity. Methods: This prospective analysis included 7144 individuals with a mean age of 67 ± 6.2 years, from the PREvención con DIeta MEDiterránea (PREDIMED) study. BMI and WC were measured and LTPA was recorded using the Minnesota Leisure Time Physical Activity Questionnaire. Exposure and outcome variables were calculated as cumulative average of repeated measurements. Results: Total LTPA was inversely associated (P < 0.001) with BMI and WC. The difference in BMI and WC between extreme quintiles of LTPA (Q1-Q5) was 2.1 kg/m2 (95% confidence interval (CI) 1.68; 2.49, P < 0.001) and 4.8 cm (CI 2.28; 7.25, P < 0.001), respectively. Low-intensity LTPA was inversely associated with BMI but not with WC, while moderate/vigorous LTPA showed an inverse relationship with BMI and WC. The hazard of general and abdominal obesity incidence decreased across quintiles of total and moderate/vigorous LTPA (P < 0.001 for both), whereas low-intensity LTPA was inversely associated with the incidence of general obesity (P < 0.001). Conclusion: LTPA was inversely associated with BMI, WC and incidence of general and abdominal obesity. The finding that low-intensity LTPA was inversely related to BMI and the incidence of obesity is of particular importance because this level of physical activity could be a feasible option for many older adults.