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1.
Matern Child Nutr ; : e13688, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886171

RESUMEN

We examined the association between serum aflatoxin B1-lysine adduct (AFB1-lys) levels in pregnant women and adverse pregnancy outcomes (low birthweight, miscarriage and stillbirth) through a nested matched case-control study of pregnant women enroled at ≤28 weeks' gestation in Mombasa, Kenya, from 2017 to 2019. Cases comprised women with an adverse birth outcome, defined as either delivery of a singleton infant weighing <2500 g, or a miscarriage, or a stillbirth, while controls were women who delivered a singleton live infant with a birthweight of ≥2500 g. Cases were matched to controls at a ratio of 1:2 based on maternal age at enrolment, gestational age at enrolment and study site. The primary exposure was serum AFB1-lys. The study included 125 cases and 250 controls. The median gestation age when serum samples were collected was 23.0 weeks (interquartile range [IQR]: 18.1-26.0) and 23.5 (IQR: 18.1-26.5) among cases and controls, respectively. Of the 375 tested sera, 145 (38.7%) had detectable serum AFB1-lys: 36.0% in cases and 40.0% in controls. AFB1-lys adduct levels were not associated with adverse birth outcomes on multivariable analysis. Mid-upper arm circumference was associated with a 6% lower odds of adverse birth outcome for every unit increase (p = 0.023). Two-fifths of pregnant women had detectable levels of aflatoxin midway through pregnancy. However, we did not detect an association with adverse pregnancy outcomes, likely because of low serum AFB1-lys levels and low power, restricting meaningful comparison. More research is needed to understand the public health risk of aflatoxin in pregnant women to unborn children.

2.
PLOS Glob Public Health ; 4(4): e0002968, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38630844

RESUMEN

The COVID-19 pandemic caused widespread changes and disruptions to healthcare seeking behavior. There are limited studies on the effect of the COVID-19 pandemic on healthcare seeking patterns in low-and middle-income countries (LMICs), especially in settings with inequitable access to healthcare in rural and urban informal settlements. We investigated the effect of the COVID-19 pandemic on reported healthcare seeking at health facilities and chemists using morbidity data from participants in an ongoing population-based infectious disease surveillance platform in Asembo in Siaya County, a rural setting in western Kenya and Kibera, an urban informal settlement in Nairobi County. We described healthcare seeking patterns before (from 1st January 2016 to 12th March 2020) and during the pandemic (from 13th March 2020 to 31st August 2022) by gender and age for any reported illness and select clinical syndromes using frequencies and percentages. We used a generalized estimating equation with an exchangeable correlation structure to assess the effect of the pandemic on healthcare seeking adjusting for gender and age. Overall, there was a 19% (adjusted odds ratio, aOR: 0.81; 95% Confidence Interval, CI: 0.79-0.83) decline in odds of seeking healthcare at health facilities for any illness in Asembo during the pandemic, and a 30% (aOR: 0.70; 95% CI: 0.67-0.73) decline in Kibera. Similarly, there was a decline in seeking healthcare by clinical syndromes, e.g., for ARI, aOR: 0.76; 95% CI:0.73-0.79 in Asembo, and aOR: 0.68; 95% CI:0.64-0.72 in Kibera. The pandemic resulted in increased healthcare seeking at chemists (aOR: 1.23; 95% CI: 1.20-1.27 in Asembo, and aOR: 1.40; 95% CI: 1.35-1.46 in Kibera). This study highlights interruptions to healthcare seeking in resource-limited settings due to the COVID-19 pandemic. The pandemic resulted in a substantial decline in seeking care at health facilities, and an increase of the same at chemists.

3.
Epidemiol Infect ; 152: e68, 2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38305089

RESUMEN

Women infected during pregnancy with TORCH (Toxoplasmosis, Other, Rubella, Cytomegalovirus, and Herpes simplex viruses) pathogens have a higher risk of adverse birth outcomes including stillbirth / miscarriage because of mother-to-child transmission. To investigate these risks in pregnant women in Kenya, we analyzed serum specimens from a pregnancy cohort study at three healthcare facilities. A sample of 481 participants was selected for TORCH pathogen antibody testing to determine seroprevalence. A random selection of 285 from the 481 participants was selected to measure seroconversion. These sera were tested using an IgG enzyme-linked immunosorbent assay against 10 TORCH pathogens. We found that the seroprevalence of all but three of the 10 TORCH pathogens at enrollment was >30%, except for Bordetella pertussis (3.8%), Treponema pallidum (11.4%), and varicella zoster virus (0.5%). Conversely, very few participants seroconverted during their pregnancy and were herpes simplex virus type 2 (n = 24, 11.2%), parvovirus B19 (n = 14, 6.2%), and rubella (n = 12, 5.1%). For birth outcomes, 88% of the participant had live births and 12% had stillbirths or miscarriage. Cytomegalovirus positivity at enrolment had a statistically significant positive association with a live birth outcome (p = 0.0394). Of the 10 TORCH pathogens tested, none had an association with adverse pregnancy outcome.


Asunto(s)
Infecciones por Citomegalovirus , Complicaciones Infecciosas del Embarazo , Rubéola (Sarampión Alemán) , Seroconversión , Humanos , Femenino , Embarazo , Estudios Seroepidemiológicos , Kenia/epidemiología , Adulto , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/virología , Rubéola (Sarampión Alemán)/epidemiología , Infecciones por Citomegalovirus/epidemiología , Adulto Joven , Herpes Simple/epidemiología , Estudios de Cohortes , Toxoplasmosis/epidemiología , Adolescente , Anticuerpos Antivirales/sangre
4.
Gates Open Res ; 7: 101, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37990692

RESUMEN

Background: SARS-CoV-2 has extensively spread in cities and rural communities, and studies are needed to quantify exposure in the population. We report seroprevalence of SARS-CoV-2 in two well-characterized populations in Kenya at two time points. These data inform the design and delivery of public health mitigation measures. Methods: Leveraging on existing population based infectious disease surveillance (PBIDS) in two demographically diverse settings, a rural site in western Kenya in Asembo, Siaya County, and an urban informal settlement in Kibera, Nairobi County, we set up a longitudinal cohort of randomly selected households with serial sampling of all consenting household members in March and June/July 2021. Both sites included 1,794 and 1,638 participants in the March and June/July 2021, respectively. Individual seroprevalence of SARS-CoV-2 antibodies was expressed as a percentage of the seropositive among the individuals tested, accounting for household clustering and weighted by the PBIDS age and sex distribution. Results: Overall weighted individual seroprevalence increased from 56.2% (95%CI: 52.1, 60.2%) in March 2021 to 63.9% (95%CI: 59.5, 68.0%) in June 2021 in Kibera. For Asembo, the seroprevalence almost doubled from 26.0% (95%CI: 22.4, 30.0%) in March 2021 to 48.7% (95%CI: 44.3, 53.2%) in July 2021. Seroprevalence was highly heterogeneous by age and geography in these populations-higher seroprevalence was observed in the urban informal settlement (compared to the rural setting), and children aged <10 years had the lowest seroprevalence in both sites. Only 1.2% and 1.6% of the study participants reported receipt of at least one dose of the COVID-19 vaccine by the second round of serosurvey-none by the first round. Conclusions: In these two populations, SARS-CoV-2 seroprevalence increased in the first 16 months of the COVID-19 pandemic in Kenya. It is important to prioritize additional mitigation measures, such as vaccine distribution, in crowded and low socioeconomic settings.

5.
Front Med (Lausanne) ; 10: 1222772, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37901408

RESUMEN

Introduction: Measurement error in gestational age (GA) may bias the association of GA with a health outcome. Ultrasound-based GA is considered the gold standard and is not readily available in low-resource settings. We corrected for measurement error in GA based on fundal height (FH) and date of last menstrual period (LMP) using ultrasound from the sub-cohort and adjusted for the bias in associating GA with neonatal mortality and low birth weight (< 2,500 grams, LBW). Methods: We used data collected from 01/2015 to 09/2019 from pregnant women enrolled at two public hospitals in Siaya county, Kenya (N = 2,750). We used regression calibration to correct for measurement error in FH- and LMP-based GA accounting for maternal and child characteristics. We applied logistic regression to associate GA with neonatal mortality and low birth weight, with and without calibrating FH- and LMP-based GA. Results: Calibration improved the precision of LMP (correlation coefficient, ρ from 0.48 to 0.57) and FH-based GA (ρ from 0.82 to 0.83). Calibrating FH/LMP-based GA eliminated the bias in the mean GA estimates. The log odds ratio that quantifies the association of GA with neonatal mortality increased by 29% (from -0.159 to -0.205) by calibrating FH-based GA and by more than twofold (from -0.158 to -0.471) by calibrating LMP-based GA. Conclusion: Calibrating FH/LMP-based GA improved the accuracy and precision of GA estimates and strengthened the association of GA with neonatal mortality/LBW. When assessing GA, neonatal public health and clinical interventions may benefit from calibration modeling in settings where ultrasound may not be fully available.

6.
PLOS Glob Public Health ; 3(8): e0002141, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37611028

RESUMEN

Robust data on the impact of the COVID-19 pandemic on mortality in Africa are relatively scarce. Using data from two well-characterized populations in Kenya we aimed to estimate excess mortality during the COVID-19 pandemic period. The mortality data arise from an ongoing population-based infectious disease surveillance (PBIDS) platform, which has been operational since 2006 in rural western Kenya (Asembo, Siaya County) and an urban informal settlement (Kibera, Nairobi County), Kenya. PBIDS participants were regularly visited at home (2-3 times a year) by field workers who collected demographic data, including deaths. In addition, verbal autopsy (VA) interviews for all identified deaths are conducted. We estimated all-cause and cause-specific mortality rates before and during the height of the COVID-19 pandemic, and we compared associated mortality rates between the periods using incidence rate ratios. Excess deaths during the COVID-19 period were also estimated by modelling expected deaths in the absence of COVID-19 by applying a negative binomial regression model on historical mortality data from January 2016. Overall and monthly excess deaths were determined using the P-score metric. Spearman correlation was used to assess whether there is a relationship between the generated P-score and COVID-19 positivity rate. The all-cause mortality rate was higher during the COVID-19 period compared to the pre-COVID-19 period in Asembo [9.1 (95% CI, 8.2-10.0) vs. 7.8 (95% CI, 7.3-8.3) per 1000 person-years of observation, pyo]. In Kibera, the all-cause mortality rate was slightly lower during the COVID-19 period compared to the pre-COVID-19 period [2.6 (95% CI, 2.2-3.2 per 1000 pyo) vs. 3.1; 95% CI, 2.7-3.4 per 1000 pyo)]. An increase in all-cause mortality was observed (incidence rate ratio, IRR, 1.16; 95% CI, 1.04-1.31) in Asembo, unlike in Kibera (IRR, 0.88; 95% CI, 0.71-1.09). The notable increase in mortality rate in Asembo was observed among persons aged 50 to 64 years (IRR, 2.62; 95% CI, 1.95-3.52), persons aged 65 years and above (5.47; 95% CI, 4.60-6.50) and among females (IRR, 1.25; 95% CI, 1.07-1.46). These age and gender differences were not observed in Kibera. We observed an increase in the mortality rate due to acute respiratory infection, including pneumonia (IRR, 1.45;95% CI, 1.03-2.04), and a reduction in the mortality rate due to pulmonary tuberculosis (IRR, 0.22; 95% CI, 0.05-0.87) among older children and adults in Asembo. There was no statistically significant change in mortality rates due to leading specific causes of death in Kibera. Overall, during the COVID-19 period observed deaths were higher than expected deaths in Asembo (P-score = 6.0%) and lower than expected in Kibera (P-score = -22.3%).Using well-characterized populations in the two diverse geographic locations, we demonstrate a heterogenous impact of the COVID-19 pandemic on all-cause and cause-specific mortality rates in Kenya. We observed more deaths than expected during the COVID-19 period in our rural site in western Kenya contrary to the urban site in Nairobi, the capital city in Kenya.

7.
Glob Health Action ; 16(1): 2238428, 2023 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-37490025

RESUMEN

BACKGROUND: Reliable mortality data are important for evaluating the impact of health interventions. However, data on mortality patterns among populations living in urban informal settlements are limited. OBJECTIVES: To examine the mortality patterns and trends in an urban informal settlement in Kibera, Nairobi, Kenya. METHODS: Using data from a population-based surveillance platform we estimated overall and cause-specific mortality rates for all age groups using person-year-observation (pyo) denominators and using Poisson regression tested for trends in mortality rates over time. We compared associated mortality rates across groups using incidence rate ratios (IRR). Assignment of probable cause(s) of death was done using the InterVA-4 model. RESULTS: We registered 1134 deaths from 2009 to 2018, yielding a crude mortality rate of 4.4 (95% Confidence Interval [CI]4.2-4.7) per 1,000 pyo. Males had higher overall mortality rates than females (incidence rate ratio [IRR], 1.44; 95% CI, 1.28-1.62). The highest mortality rate was observed among children aged < 12 months (41.5 per 1,000 pyo; 95% CI 36.6-46.9). All-cause mortality rates among children < 12 months were higher than that of children aged 1-4 years (IRR, 8.5; 95% CI, 6.95-10.35). The overall mortality rate significantly declined over the period, from 6.7 per 1,000 pyo (95% CI, 5.7-7.8) in 2009 to 2.7 (95% CI, 2.0-3.4) per 1,000 pyo in 2018. The most common cause of death was acute respiratory infections (ARI)/pneumonia (18.1%). Among children < 5 years, the ARI/pneumonia deaths rate declined significantly over the study period (5.06 per 1,000 pyo in 2009 to 0.61 per 1,000 pyo in 2018; p = 0.004). Similarly, death due to pulmonary tuberculosis among persons 5 years and above significantly declined (0.98 per 1,000 pyo in 2009 to 0.25 per 1,000 pyo in 2018; p = 0.006). CONCLUSIONS: Overall and some cause-specific mortality rates declined over time, representing important public health successes among this population.


Asunto(s)
Infecciones del Sistema Respiratorio , Tuberculosis Pulmonar , Niño , Femenino , Masculino , Humanos , Kenia , Vigilancia de la Población , Salud Pública
8.
Am J Clin Nutr ; 118(1): 218-227, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37150507

RESUMEN

BACKGROUND: At present, the results on the associations between dietary patterns and risk of dementia are inconsistent, and studies on the associations between dietary patterns and brain structures are limited. OBJECTIVES: We aimed to investigate the associations of midlife dietary patterns with incident dementia and brain structures. METHODS: On the basis of the UK Biobank Study, we investigated the 1) prospective associations of 4 healthy dietary pattern indices [healthy plant-based diet index (hPDI), Mediterranean diet score (MDS), recommended food score (RFS), and Mediterranean-DASH Intervention for Neurodegenerative Delay Diet (MIND)] with incident dementia (identified using linked hospital data; N = 114,684; mean age, 56.8 y; 55.5% females) using Cox proportional-hazards regressions and the 2) cross-sectional associations of these dietary pattern indices with brain structures (estimated using magnetic resonance imaging; N = 18,214; mean age, 55.9 y; 53.1% females) using linear regressions. A series of covariates were adjusted, and several sensitivity analyses were conducted. RESULTS: A total of 481 (0.42%) participants developed dementia during the average 9.4-y follow-up. Although the associations were not statistically significant, all dietary patterns exerted protective effects against incident dementia (all HRs < 1). Furthermore, higher dietary pattern indices were significantly associated with larger regional brain volumes, including volumes of gray matter in the parietal and temporal cortices and volumes of the hippocampus and thalamus. The main results were confirmed via sensitivity analyses. CONCLUSIONS: Greater adherence to hPDI, MDS, RFS, and MIND was individually associated with larger brain volumes in specific regions. This study shows a comprehensive picture of the consistent associations of midlife dietary patterns with risk of dementia and brain health, underscoring the potential benefits of a healthy diet in the prevention of dementia.


Asunto(s)
Demencia , Dieta Mediterránea , Femenino , Humanos , Persona de Mediana Edad , Masculino , Estudios Transversales , Bancos de Muestras Biológicas , Encéfalo/diagnóstico por imagen , Demencia/epidemiología , Demencia/prevención & control , Reino Unido/epidemiología
9.
Am J Trop Med Hyg ; 109(1): 22-31, 2023 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-37253442

RESUMEN

Typhoid fever burden can vary over time. Long-term data can inform prevention strategies; however, such data are lacking in many African settings. We reexamined typhoid fever incidence and antimicrobial resistance (AMR) over a 10-year period in Kibera, a densely populated urban informal settlement where a high burden has been previously described. We used data from the Population Based Infectious Diseases Surveillance platform to estimate crude and adjusted incidence rates and prevalence of AMR in nearly 26,000 individuals of all ages. Demographic and healthcare-seeking information was collected through household visits. Blood cultures were processed for patients with acute fever or lower respiratory infection. Between 2010 and 2019, 16,437 participants were eligible for blood culture and 11,848 (72.1%) had a culture performed. Among 11,417 noncontaminated cultures (96.4%), 237 grew Salmonella enterica serovar Typhi (2.1%). Overall crude and adjusted incidences were 95 and 188 cases per 100,000 person-years of observation (pyo), respectively. Annual crude incidence varied from 144 to 233 between 2010 and 2012 and from 9 to 55 between 2013 and 2018 and reached 130 per 100,000 pyo in 2019. Children 5-9 years old had the highest overall incidence (crude, 208; adjusted, 359 per 100,000 pyo). Among isolates tested, 156 of 217 were multidrug resistant (resistant to chloramphenicol, ampicillin, and trimethoprim/sulfamethoxazole [71.9%]) and 6 of 223 were resistant to ciprofloxacin (2.7%). Typhoid fever incidence resurged in 2019 after a prolonged period of low rates, with the highest incidence among children. Typhoid fever control measures, including vaccines, could reduce morbidity in this setting.


Asunto(s)
Fiebre Tifoidea , Niño , Humanos , Preescolar , Fiebre Tifoidea/epidemiología , Incidencia , Kenia/epidemiología , Salmonella typhi , Ciprofloxacina/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico
10.
Ann Epidemiol ; 82: 8-15, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36972757

RESUMEN

PURPOSE: A substantial proportion of global deaths is attributed to unhealthy diets, which can be assessed at baseline or longitudinally. We demonstrated how to simultaneously correct for random measurement error, correlations, and skewness in the estimation of associations between dietary intake and all-cause mortality. METHODS: We applied a multivariate joint model (MJM) that simultaneously corrected for random measurement error, skewness, and correlation among longitudinally measured intake levels of cholesterol, total fat, dietary fiber, and energy with all-cause mortality using US National Health and Nutrition Examination Survey linked to the National Death Index mortality data. We compared MJM with the mean method that assessed intake levels as the mean of a person's intake. RESULTS: The estimates from MJM were larger than those from the mean method. For instance, the logarithm of hazard ratio for dietary fiber intake increased by 14 times (from -0.04 to -0.60) with the MJM method. This translated into a relative hazard of death of 0.55 (95% credible interval: 0.45, 0.65) with the MJM and 0.96 (95% credible interval: 0.95, 0.97) with the mean method. CONCLUSIONS: MJM adjusts for random measurement error and flexibly addresses correlations and skewness among longitudinal measures of dietary intake when estimating their associations with death.


Asunto(s)
Dieta , Ingestión de Alimentos , Humanos , Encuestas Nutricionales , Dieta/efectos adversos , Modelos de Riesgos Proporcionales , Estudios Epidemiológicos
11.
Am J Clin Nutr ; 117(1): 1-11, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36789928

RESUMEN

BACKGROUND: Little is known regarding the association between weight change and accelerated aging. OBJECTIVES: This study aimed to estimate the influence of weight change across adulthood on biological aging acceleration in middle-aged and older adults in the United States. METHODS: We used data of 5553 adults (40-84 y) from the National Health and Nutrition Examination Survey 1999-2010. Weight change patterns (i.e., stable normal, maximal overweight, obese to nonobese, nonobese to obese, and stable obese) and absolute weight change groups across adulthood (i.e., from young to middle adulthood, young to late adulthood, and middle to late adulthood) were defined. A biological aging measure (i.e., phenotypic age acceleration [PhenoAgeAccel]) at late adulthood was calculated. Survey analysis procedures with the survey weights were performed. RESULTS: Across adulthood, maximal overweight, nonobese to obese, and stable obesity were consistently associated with higher PhenoAgeAccel. For instance, from young to middle adulthood, compared with participants who had stable normal weight, participants experiencing maximal overweight, moving from the nonobese to obese, and maintaining obesity had 1.71 (standard error [SE], 0.21; P < 0.001), 3.62 (SE, 0.28; P < 0.001), and 6.61 (SE, 0.58; P < 0.001) higher PhenoAgeAccel values, respectively. From young to middle adulthood, relative to absolute weight loss or gain of <2.5 kg, weight loss of ≥2.5 kg was marginally associated with lower PhenoAgeAccel (P = 0.054), whereas an obese to nonobese pattern from middle to late adulthood was associated with higher PhenoAgeAccel (P < 0.001). CONCLUSIONS: Maximal overweight, nonobese to obese, and stable obesity across adulthood, as well as an obese to nonobese pattern from middle to late adulthood, were associated with accelerated biological aging. In contrast, weight loss from young to middle adulthood was associated with decelerated biological aging. The findings highlight the potential role of weight management across adulthood for aging. Monitoring weight fluctuation may help identify the population at high risk of accelerated aging.


Asunto(s)
Obesidad , Sobrepeso , Persona de Mediana Edad , Humanos , Estados Unidos , Anciano , Adulto , Sobrepeso/epidemiología , Índice de Masa Corporal , Encuestas Nutricionales , Obesidad/epidemiología , Envejecimiento , Pérdida de Peso , Factores de Riesgo
12.
J Am Acad Dermatol ; 89(1): 70-80, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31473294

RESUMEN

BACKGROUND: Previous work has suggested that facility-level characteristics, such as case volume and academic affiliation, are associated with patient survival for rare malignancies. Merkel cell carcinoma (MCC) is a rare neuroendocrine skin cancer with high mortality and rising incidence. The effect of facility characteristics on MCC outcomes is not yet established. OBJECTIVE: We aimed to investigate whether facility academic affiliation or case volume was associated with MCC patient survival. METHODS: We conducted a retrospective cohort analysis of US adult MCC cases diagnosed during 2004-2014 in the National Cancer Database. RESULTS: Both facility academic affiliation (P < .001) and case volume (P < .001) were significantly associated with patient survival. The 5-year survival of patients treated at academic facilities was 63.0% (standard error [SE] 1.7) and that of a propensity score- matched cohort of patients treated at nonacademic facilities was 53.4% (SE 1.9). The 5-year survival of patients treated at high-case volume facilities was 67.4% (SE 2.1) and that of a propensity score-matched cohort of patients treated at low- and intermediate-case volume facilities was 58.6% (SE 2.0). LIMITATIONS: Disease-specific survival and local recurrence data were not available. CONCLUSION: Treatment of MCC at academic and high-volume centers is associated with significantly improved patient survival. Further studies evaluating comorbidities and disease-specific survival are needed to establish whether experienced centers have improved outcomes in MCC treatment.


Asunto(s)
Carcinoma de Células de Merkel , Neoplasias Cutáneas , Adulto , Humanos , Carcinoma de Células de Merkel/epidemiología , Carcinoma de Células de Merkel/terapia , Estudios Retrospectivos , Neoplasias Cutáneas/epidemiología , Neoplasias Cutáneas/terapia , Estadificación de Neoplasias , Estudios de Cohortes
13.
J Appl Stat ; 49(4): 884-901, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35707818

RESUMEN

Exposure measurement error (ME) biases exposure-outcome associations. Calibration dietary intake data used in the regression calibration (RC) response to adjust for ME are usually right-skewed, heteroscedastic and with excess zeroes. We proposed three-part RC models to handle these distributional complexities simultaneously, while correcting for ME in fish intake. We applied data from the National Health and Nutrition Examination Survey (NHANES), where long-term intake was measured with food frequency questionnaire (FFQ) in the main study and short-term intake with 24-hour recall (24HR) in the calibration study. In the three-part RC models, never consumers were modelled using two approaches: a zero distribution (Three-part RC-het-det), and logistic distribution (Three-part RC-het-prob); heteroscedasticity using an exponential distribution and right-skewness using generalized gamma distribution. The proposed models were compared with two-part RC model that ignores never consumers, and with methods that estimate intakes using FFQ and 24HR. The models were evaluated in a simulation study. With NHANES data, mean increase in the mercury level (in µ g / L ) was 1.20 using FFQ-method, 0.4 using 24HR-method, 1.87 using two-part RC and 2.02 using three-part RC-het-prob method. The three-part RC estimated the association with the least bias in the simulation study.

14.
Behav Res Methods ; 54(6): 2949-2961, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35132587

RESUMEN

Longitudinal studies of correlated cognitive and disability outcomes among older adults are characterized by missing data due to death or loss to follow-up from deteriorating health conditions. The Mini-Mental State Examination (MMSE) score for assessing cognitive function ranges from a minimum of 0 (floor) to a maximum of 30 (ceiling). To study the risk factors of cognitive function and functional disability, we propose a shared parameter model to handle missingness, correlation between outcomes, and the floor and ceiling effects of the MMSE measurements. The shared random effects in the proposed model handle missingness (either missing at random or missing not at random) and correlation between these outcomes, while the Tobit distribution handles the floor and ceiling effects of the MMSE measurements. We used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) and a simulation study. By ignoring the MMSE floor and ceiling effects in the analyses of the CLHLS, the association of systolic blood pressure with cognitive function was not significant and the association of age with cognitive function was lower by 16.6% (from -6.237 to -5.201). By ignoring the MMSE floor and ceiling effects in the simulation study, the relative bias in the estimated association of female gender with cognitive function was 43 times higher (from -0.01 to -0.44). The estimated associations obtained with data missing at random were smaller than those with data missing not at random, demonstrating how the missing data mechanism affects the analytic results. Our work underscores the importance of proper model specification in longitudinal analysis of correlated outcomes subject to missingness and bounded values.


Asunto(s)
Cognición , Humanos , Femenino , Anciano , Estudios Longitudinales
15.
Alzheimers Dement (N Y) ; 7(1): e12193, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34401467

RESUMEN

INTRODUCTION: More persons with dementia are residing in the community as many countries shift from residential care to home and community care. Although there are many forms of care and support available to avoid crisis situations and prolong community living, it remains unclear how these are valued by community-dwelling persons with dementia and their informal caregivers. Understanding perspectives of persons with dementia and informal caregivers on care characteristics is a vital step in valuing care services. This study aims to prioritize care characteristics for community-dwelling persons with dementia and informal caregivers with the use of an innovative mixed-methods approach. METHODS: Six mixed focus groups were conducted in The Netherlands with persons with dementia (n = 23) and informal caregivers (n = 20), including a quantitative ranking exercise that prioritized seven care and support characteristics from "most important" to "least important," followed by a group discussion about the prioritization. Audio recordings were transcribed and analyzed using thematic analysis. RESULTS: The ranking exercise and discussion showed that persons with dementia favored in-home care, help with daily activities, and social activities, whereas informal caregivers favored social activities, information about dementia, navigating the health care system, and emotional support. DISCUSSION: Persons with dementia prioritized day-to-day activities, whereas informal caregivers preferred assistance with organizing care and coping with caregiving. This study created a method to capture the care preferences of persons with dementia and informal caregivers.

16.
Australas J Dermatol ; 62(3): 323-330, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34028790

RESUMEN

BACKGROUND: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin cancer with a high mortality rate. MCC staging is currently based on tumour primary size, clinical detectability of lymph node metastases, performance of a lymph node biopsy, and presence of distant metastases. OBJECTIVE: We aimed to use a modified classification and regression tree (CART) algorithm using available data points in the National Cancer Database (NCDB) to elucidate novel prognostic factors for MCC. METHODS: Retrospective cohort study of the NCDB and Surveillance, Epidemiology, and End Results (SEER) registries. Cases from the NCDB were randomly assigned to either the training or validation cohorts. A modified CART algorithm was created with data from the training cohort and used to identify prognostic groups that were validated in the NCDB validation and SEER cohorts. RESULTS: A modified CART algorithm using tumour variables available in the NCDB identified prognostic strata as follows: I: local disease, II: ≤3 positive nodes, III: ≥4 positive nodes, and IV: presence of distant metastases. Three-year survival for these groups in the NCDB validation cohort were 81.2% (SE: 1.7), 59.6% (SE: 3.0), 38.0% (SE: 6.0), and 20.2% (SE: 7.0), respectively. These strata were exhibited greater within-group homogeneity than AJCC groups and were more predictive of survival. CONCLUSIONS: Risk-stratified grouping of MCC patients incorporating positive lymph node count were strongly predictive of survival and demonstrated a high degree of within-group homogeneity and survival prediction. Incorporation of positive lymph node count within overall staging or sub-staging may help to improve future MCC staging criteria.


Asunto(s)
Algoritmos , Biomarcadores de Tumor/análisis , Carcinoma de Células de Merkel/patología , Invasividad Neoplásica/patología , Neoplasias Cutáneas/patología , Adulto , Anciano , Carcinoma de Células de Merkel/clasificación , Simulación por Computador , Vías Clínicas , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales , Neoplasias Cutáneas/clasificación , Adulto Joven
17.
Aging (Albany NY) ; 12(22): 23129-23145, 2020 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-33221750

RESUMEN

Our objectives were to evaluate: 1) the associations of cognitive frailty with various health outcomes including disability, hospitalization, and death; 2) whether the associations differed by multimorbidity. We included data of 5113 Chinese older adults (aged 60+ years) who had baseline cognition and physical frailty assessments (2011 wave) and follow-up for 4 years. About 16.0% (n=820) had cognitive impairment; 6.7% (n=342) had physical frailty; and 1.6% (n=82) met criteria for cognitive frailty. Both cognitive impairment (odds ratios (ORs) range: 1.41 to 2.11) and physical frailty (ORs range: 1.51 to 2.43) were independently associated with basic activities of daily living (BADL), instrumental ADL (IADL), mobility disability, hospitalization, and death among participants without that corresponding outcome at baseline, even after accounting for covariates. Relative to participants who had normal cognition and were nonfrail, those with cognitive frailty had the highest risk for IADL disability (OR=3.40, 95% CI, 1.23-9.40) and death (OR=3.89, 95% CI, 2.25-6.47). We did not find significant interaction effects between cognitive frailty and multimorbidity (Pinteractions>0.05). Overall, cognitive frailty was associated with disability and death, independent of multimorbidity. This highlights the importance of assessing cognitive frailty in the community to promote primary and secondary preventions for healthy aging.


Asunto(s)
Cognición , Envejecimiento Cognitivo/psicología , Disfunción Cognitiva/psicología , Anciano Frágil/psicología , Fragilidad/psicología , Actividades Cotidianas , Factores de Edad , Anciano , Anciano de 80 o más Años , China/epidemiología , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/mortalidad , Disfunción Cognitiva/fisiopatología , Evaluación de la Discapacidad , Femenino , Fragilidad/diagnóstico , Fragilidad/mortalidad , Fragilidad/fisiopatología , Estado Funcional , Encuestas Epidemiológicas , Hospitalización , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Limitación de la Movilidad , Multimorbilidad , Pronóstico , Jubilación , Medición de Riesgo , Factores de Riesgo
19.
Exp Gerontol ; 134: 110886, 2020 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-32088398

RESUMEN

OBJECTIVE: In an 8-week nonpharmacological pain intervention trial among older adults with lower extremity osteoarthritis (OA), we aimed to examine: a) the baseline frailty level of the participants; b) whether such intervention is more beneficial for baseline frailer older adults than for their counterparts with less frailty; and c) whether the intervention could also alter frailty. METHODS: Participants were randomly assigned to either chair yoga (CY) or health education program (HEP) groups and attended twice-weekly 45-minute CY or HEP sessions for 8 weeks. Following a standard procedure, 82 variables were used to construct a frailty index (FI, 0-1). Primary outcomes were: Western Ontario and McMaster Universities (WOMAC) pain and pain interference. Linear mixed-effects models were used to evaluate the modifying effect of baseline frailty on the intervention effect of CY on primary outcomes. Similar models were used to evaluate the effect of CY on frailty. RESULTS: A total of 112 participants (n = 63 CY, n = 49 HEP; 75.3 [SD = 7.5] years) with 85 females (75.9%) were included. The mean values of baseline FI for the CY and HEP groups were similar (0.428 [0.05] and 0.433 [0.05], P = 0.355). Each 0.01 increment in baseline FI was associated with higher WOMAC pain (beta = 0.28, P < 0.001) and pain interference (beta = 0.51, P < 0.001). There was a significant interaction effect between intervention, time, and baseline FI (P = 0.020 for WOMAC pain; P = 0.010 for pain interference), indicating that participants with higher level of baseline FI had greater declines in WOMAC pain and pain interference. There was no significantly greater decline in FI for the CY group compared to the HEP group (between-group difference - 0.01; P = 0.509) and there were no significant trend changes in FI (P for interaction = 0.605). CONCLUSIONS: Frailty modifies the intervention effect of CY on pain among older adults with lower extremity OA, underscoring the importance of assessing frailty to improve the management of pain in this population.

20.
Perm J ; 242020.
Artículo en Inglés | MEDLINE | ID: mdl-31905337

RESUMEN

INTRODUCTION: Electronic health care data offer an opportunity to improve clinical decision making through advanced statistical analyses of longitudinal observations. OBJECTIVE: To describe a Web application and SAS/STAT macro (SAS Institute Inc, Cary, NC) for computing joint models to estimate the typical and personalized risk of 2 concurrent binary outcomes. METHODS: Features of the Web application design include uploading longitudinal files formatted with constant or time-varying covariates, specification of 2 binary outcomes, specification of a propensity model for treatment, and joint and separate models of the outcomes. In addition we designed an SAS macro for conducting the analysis. Fitting of joint and separate statistical models was implemented using a model specified in the Web application, with subsequent processing by the SAS macro. To illustrate the fitting of models, a sample of older adults with comorbid hypertension and chronic obstructive pulmonary disease from the Medical Expenditure Panel Survey was created to examine the association between polypharmacy (use of ≥ 5 medication classes) and limitations in social activities and mobility. RESULTS: Relative to separate models, the joint models typically estimated attenuated associations between explanatory variables and the 2 outcomes with smaller standard errors. These joint models yielded estimates of personalized concurrent risk and typical concurrent risk. DISCUSSION: Clinical decision making based on electronic health data can be improved using joint modeling to generate an individual's probability of concurrent risk. CONCLUSION: This user-friendly software performs the advanced statistical analyses needed to estimate typical and personalized concurrent risks.


Asunto(s)
Toma de Decisiones Clínicas/métodos , Modelos Estadísticos , Medicina de Precisión/métodos , Humanos , Internet , Medición de Riesgo , Programas Informáticos
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