Compared to what? Finding controls for case-control studies

Association of smoking status with hospitalisation for COVID-19 compared with other respiratory viruses a year previous: a case-control study at a single UK National Health Service trust

Background: It is unclear whether smoking increases the risk of COVID-19 hospitalisation. We first examined the association of smoking status with hospitalisation for COVID-19 compared with hospitalisation for other respiratory viral infections a year previous. Second, we examined the concordance between smoking status recorded on the electronic health record (EHR) and the contemporaneous medical notes. Methods: This case-control study enrolled adult patients (446 cases and 211 controls) at a single National Health Service trust in London, UK. The outcome variable was type of hospitalisation (COVID-19 vs. another respiratory virus a year previous). The exposure variable was smoking status (never/former/current smoker). Logistic regression analyses adjusted for age, sex, socioeconomic position and comorbidities were performed. The study protocol and analyses were pre-registered in April 2020 on the Open Science Framework. Results: Current smokers had lower odds of being hospitalised with COVID-19 compared with other respiratory viruses a year previous (OR adj=0.55, 95% CI=0.31-0.96,  p=.04). There was no significant association among former smokers (OR adj=1.08, 95% CI=0.72-1.65,  p=.70). Smoking status recorded on the EHR (compared with the contemporaneous medical notes) was incorrectly recorded for 168 (79.6%) controls (χ 2(3)=256.5,  p=<0.001) and 60 cases (13.5%) (χ 2(3)=34.2,  p=<0.001). Conclusions: In a single UK hospital trust, current smokers had reduced odds of being hospitalised with COVID-19 compared with other respiratory viruses a year previous, although it is unclear whether this association is causal. Targeted post-discharge recording of smoking status may account for the greater EHR-medical notes concordance observed in cases compared with controls.

Association of smoking status with hospitalisation for COVID-19 compared with other respiratory viruses a year previous: a case-control study at a single UK National Health Service trust

Background: It is unclear whether smoking increases the risk of COVID-19 hospitalisation. We first examined the association of smoking status with hospitalisation for COVID-19 compared with hospitalisation for other respiratory viral infections a year previous. Second, we examined the concordance between smoking status recorded on the electronic health record (EHR) and the contemporaneous medical notes. Methods: This case-control study enrolled adult patients (446 cases and 211 controls) at a single National Health Service trust in London, UK. The outcome variable was type of hospitalisation (COVID-19 vs. another respiratory virus a year previous). The exposure variable was smoking status (never/former/current smoker). Logistic regression analyses adjusted for age, sex, socioeconomic position and comorbidities were performed. The study protocol and analyses were pre-registered in April 2020 on the Open Science Framework. Results: Current smokers had lower odds of being hospitalised with COVID-19 compared with other respiratory viruses a year previous (OR adj=0.55, 95% CI=0.31-0.96,  p=.04). There was no significant association among former smokers (OR adj=1.08, 95% CI=0.72-1.65,  p=.70). Smoking status recorded on the EHR (compared with the contemporaneous medical notes) was incorrectly recorded for 168 (79.6%) controls (χ 2(3)=256.5,  p=<0.001) and 60 cases (13.5%) (χ 2(3)=34.2,  p=<0.001). Conclusions: In a single UK hospital trust, current smokers had reduced odds of being hospitalised with COVID-19 compared with other respiratory viruses a year previous, although it is unclear whether this association is causal. Targeted post-discharge recording of smoking status may account for the greater EHR-medical notes concordance observed in cases compared with controls.

Medial Ankle Stability Evaluation With Dynamic Ultrasound: Establishing Natural Variations in the Healthy Cohort

INTRODUCTION

Destabilizing injuries to the deltoid ligament have relied on radiographic stress examination for diagnosis, with a focus on medial clear space (MCS) widening. Recently, studies have demonstrated the use of ultrasonography to assess deltoid ligament injury, but not the medial ankle stability. The purpose of this study was to assess the MCS via ultrasonography while weight-bearing and with a gravity stress test (GST) in the uninjured ankle as a means of establishing normative values for future comparison.

METHODS

Twenty-six participants with no reported ankle injury in their premedical history were included. The MCS was examined using ultrasonography with the patient lying in a lateral decubitus position to replicate a GST with the ankle held in a neutral and plantarflexed position as well as while weight-bearing. The MCS was assessed in mm at the anteromedial and inferomedial aspect of the ankle joint.

RESULTS

With weight-bearing, the average anterior MCS and inferior MCS were 3.6 and 3.3 mm, respectively. During the GST in neutral ankle position, the average anterior MCS was 4.1 mm, whereas the average inferior MCS was 4.0 mm. When measured during the GST in plantarflexed ankle position, the averages anterior MCS and inferior MCS increased to 4.4 mm. MCS values were notably higher with GST than with weight-bearing measurements (P < 0.001). MCS values were notably higher with the foot in a plantarflexed compared with a neutral position when doing GST (P < 0.001). No notable differences in MCS distance were found when comparing laterality (P > 0.05). Height had a notable effect on all MCS values (P < 0.05). Inter- and intra-rater reliabilities for ultrasonographic MCS measurements were all excellent (interclass correlation coefficient >0.75).

DISCUSSION

Ultrasound can reliably measure the MCS of the ankle while doing dynamic stress manoeuvres. With the deltoid ligament intact, a GST increases MCS widening more than weight-bearing, and holding the ankle in plantarflexion while doing a gravity stress view, further increases this difference.

LEVELS OF EVIDENCE

Diagnostic studies-investigating a diagnostic test: Level III.

Different antecedents and neonatal condition in neonatal arterial ischemic stroke and hypoxic-ischemic neonatal encephalopathy

Objective

To define similarities and differences between neonatal arterial ischemic stroke (NAIS) and hypoxic‐ischemic neonatal encephalopathy (HINE).

Methods

A retrospective case‐control study was conducted of neonates born at 35 weeks or more and weighing 1800 g or more at a tertiary care university hospital, between 2005 and 2016, with NAIS (group A), perinatal asphyxia (PA) with Stage II–III HINE (group B), and PA with or without Stage I HINE (group C). Ante‐ and intrapartum data, neonatal characteristics, and placental histopathology were compared.

Results

Eleven neonates were identified in group A, 10 in group B, and 227 in group C. Sentinel events occurred exclusively in groups B (80%) and C (41.4%). Umbilical cord blood gas values and Apgar score were worse in groups B and C compared to group A. No group A neonates required resuscitation at birth, whereas all group B and one‐third of group C neonates did. Seizures developed only in neonates in groups A and B. One neonatal death occurred in group A. There were no significant differences in placental histopathology.

Conclusion

NAIS and PA/HINE cases have different intrapartum and neonatal features. PA does not seem necessary for the occurrence of NAIS. More research is needed regarding associated placental abnormalities.

Birth asphyxia does not seem necessary for neonatal arterial ischemic stroke occurrence. The two conditions have different ante‐/intrapartum and neonatal features.

Incorporating Real-time Influenza Detection Into the Test-negative Design for Estimating Influenza Vaccine Effectiveness: The Real-time Test-negative Design (rtTND)

With rapid and accurate molecular influenza testing now widely available in clinical settings, influenza vaccine effectiveness (VE) studies can prospectively select participants for enrollment based on real-time results rather than enrolling all eligible patients regardless of influenza status, as in the traditional test-negative design (TND). Thus, we explore advantages and disadvantages of modifying the TND for estimating VE by using real-time, clinically available viral testing results paired with acute respiratory infection eligibility criteria for identifying influenza cases and test-negative controls prior to enrollment. This modification, which we have called the real-time test-negative design (rtTND), has the potential to improve influenza VE studies by optimizing the case-to-test-negative control ratio, more accurately classifying influenza status, improving study efficiency, reducing study cost, and increasing study power to adequately estimate VE. Important considerations for limiting biases in the rtTND include the need for comprehensive clinical influenza testing at study sites and accurate influenza tests.

Risk of cancer in long-term levothyroxine users: Retrospective population-based study

Levothyroxine is a widely prescribed medication for the treatment of an underactive thyroid. The relationship between levothyroxine use and cancer risk is largely underdetermined. To investigate the magnitude of the possible association between levothyroxine use and cancer risk, this retrospective case‐control study was conducted using Taiwan’s Health and Welfare Data Science Center database. Cases were defined as all patients who were aged ≥20 years and had a first‐time diagnosis for cancer at any site for the period between 2001 and 2011. Multivariable conditional logistic regression models were used to calculate an adjusted odds ratio (AOR) to reduce potential confounding factors. A total of 601 733 cases and 2 406 932 controls were included in the current study. Levothyroxine users showed a 50% higher risk of cancer at any site (AOR: 1.50, 95% CI: 1.46‐1.54; P < .0001) compared with non–users. Significant increased risks were also observed for brain cancer (AOR: 1.90, 95% CI: 1.48‐2.44; P < .0001), skin cancer (AOR: 1.42, 95% CI: 1.17‐1.72; P < .0001), pancreatic cancer (AOR: 1.27, 95% CI: 1.01‐1.60; P = .03), and female breast cancer (AOR: 1.24, 95% CI: 1.15‐1.33; P < .0001). Our study results showed that levothyroxine use was significantly associated with an increased risk of cancer, particularly brain, skin, pancreatic, and female breast cancers. Levothyroxine remains a highly effective therapy for hypothyroidism; therefore, physicians should carefully consider levothyroxine therapy and monitor patients’ condition to avoid negative outcomes. Additional studies are needed to confirm these findings and to evaluate the potential biological mechanisms.

Using General-purpose Sentiment Lexicons for Suicide Risk Assessment in Electronic Health Records: Corpus-Based Analysis

Background

Suicide is a serious public health issue, accounting for 1.4% of all deaths worldwide. Current risk assessment tools are reported as performing little better than chance in predicting suicide. New methods for studying dynamic features in electronic health records (EHRs) are being increasingly explored. One avenue of research involves using sentiment analysis to examine clinicians’ subjective judgments when reporting on patients. Several recent studies have used general-purpose sentiment analysis tools to automatically identify negative and positive words within EHRs to test correlations between sentiment extracted from the texts and specific medical outcomes (eg, risk of suicide or in-hospital mortality). However, little attention has been paid to analyzing the specific words identified by general-purpose sentiment lexicons when applied to EHR corpora.

Objective

This study aims to quantitatively and qualitatively evaluate the coverage of six general-purpose sentiment lexicons against a corpus of EHR texts to ascertain the extent to which such lexical resources are fit for use in suicide risk assessment.

Methods

The data for this study were a corpus of 198,451 EHR texts made up of two subcorpora drawn from a 1:4 case-control study comparing clinical notes written over the period leading up to a suicide attempt (cases, n=2913) with those not preceding such an attempt (controls, n=14,727). We calculated word frequency distributions within each subcorpus to identify representative keywords for both the case and control subcorpora. We quantified the relative coverage of the 6 lexicons with respect to this list of representative keywords in terms of weighted precision, recall, and F score.

Results

The six lexicons achieved reasonable precision (0.53-0.68) but very low recall (0.04-0.36). Many of the most representative keywords in the suicide-related (case) subcorpus were not identified by any of the lexicons. The sentiment-bearing status of these keywords for this use case is thus doubtful.

Conclusions

Our findings indicate that these 6 sentiment lexicons are not optimal for use in suicide risk assessment. We propose a set of guidelines for the creation of more suitable lexical resources for distinguishing suicide-related from non–suicide-related EHR texts.

Multi-domain cognitive impairments at school age in very preterm-born children compared to term-born peers

Background

Preterm infants are at risk for functional impairments in motor, cognitive, and behavioral development that may persist into childhood. The aim of this study was to determine the co-occurrence of cognitive impairments in multiple cognitive domains at school age in very preterm born children compared to term-born children.

Methods

Comparative study including 60 very preterm-born children (gestational age ≤ 32 weeks) and 120 term-born controls. At school age, we assessed intelligence with the WISC-III, and visuomotor integration with the NEPSY-II, verbal memory with the AVLT, attention with the TEA-ch, and executive functioning with the BRIEF. We investigated co-occurrence of various abnormal (<5th percentile) and suspect-abnormal (<15th percentile, including both suspect and abnormal) cognitive functions.

Results

At mean age 8.8 years, 15% of preterm children had abnormal outcomes in multiple cognitive functions (≥2), versus 3% of the controls (odds ratio, OR 4.65, 95%-confidence interval, CI 1.33–16.35). For multiple suspect-abnormal cognitive outcomes, rates were 55% versus 25% (OR 3.02, 95%-CI 1.49–6.12). We found no pattern of co-occurrence of cognitive impairments among preterm children that deviated from term-born controls. However, low performance IQ was more frequently accompanied by additional cognitive impairments in preterms than in controls (OR 5.43, 95%-CI 1.75–16.81).

Conclusions

A majority of preterm children showed co-occurrence of impairments in multiple cognitive domains, but with no specific pattern of impairments. The occurrence of multi-domain cognitive impairments is higher in preterms but this seems to reflect a general increase, not one with a pattern specific for preterm-born children.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02641-z.

Association Between Serum Vitamin D Level and Ménière's Disease

OBJECTIVES

Ménière's disease (MD) is a well-known inner ear disease; however, the etiopathogenesis is unknown. Several factors may be involved. Meanwhile, vitamin D is reported to have an important role in inner ear physiology. The aim of this study is to evaluate the relation between vitamin D deficiency and MD.

STUDY DESIGN

This matched case-control study compared serum vitamin D levels between patients with definite MD and those without it.

SETTING

The study was done between August 2018 and December 2019 at Ghaem University Hospital in Mashhad, Iran.

METHODS

Twenty-eight patients with definite MD were matched with a group of 84 healthy individuals, regarding age, sex, body mass index, and occupation (indoor vs outdoor). The serum level of vitamin D (25-hydroxyvitamin D3) was measured in both groups.

RESULTS

The mean ± SD vitamin D level was 18.9 ± 9.7 ng/mL in the case group and 25.2 ± 13.7 ng/mL in the control group (P = .027). There was a significant difference between the case and control groups according to the results of the conditional logistic regression model (P = .03; adjusted odds ratio, 0.96). In the MD group, 17 (60.7%) patients were vitamin D deficient, 6 (21.4%) insufficient, and only 5 (17.9%) sufficient.

CONCLUSIONS

The results of this study show that serum vitamin D level in MD is significantly lower than that of the control group. However, the role of vitamin D supplementation in the management of MD needs further study.

LEVEL OF EVIDENCE

4.

Psychiatric disorders in female psychosexual disorders-a nationwide, cohort study in Taiwan : Psychiatric disorders and female psychosexual disorders

We aimed to investigate whether females with psychosexual disorders were associated with the risk of affective and other psychiatric disorders. A total of 2240 enrolled individuals, with 560 patients with psychosexual disorders and 1680 subjects without psychosexual disorders (1:3) matched for age and index year, from the Longitudinal Health Insurance Database, retrieved from the National Health Insurance Research Database (NHIRD), between 2000 and 2015 in Taiwan. The multivariate Cox regression model was used to compare the risk of developing psychiatric disorders during the 15 years of follow-up. There were 98 in the cohort with psychosexual disorders (736.07 per 100,000 person-year) and 119 in the non-cohort without psychosexual disorders (736.07 per 100,000 person-year) that developed psychiatric disorders. The multivariate Cox regression model revealed that the adjusted hazard ratio (HR) was 9.848 (95% CI = 7.298 - 13.291, p < 0.001), after the adjustment of age, monthly income, urbanization level, geographic region, and comorbidities. Female patients with psychosexual disorders were associated with the risk of psychiatric disorders. This finding could be a reminder for clinicians about the mental health problems in patients with psychosexual disorders.

Association of NAFLD and Insulin Resistance with Non Metastatic Bladder Cancer Patients: A Cross-Sectional Retrospective Study

Among risk factors (apart from smoking) likely involved in bladder cancer (BCa), metabolic syndrome (MS), obesity and type 2 diabetes mellitus (T2DM) have been explored with contrasting results. In spite of these studies, there is little data on the association between nonalcoholic fatty liver disease (NAFLD), its main driver, i.e., insulin resistance (IR), and BCa. Implanting a cross-sectional retrospective study we tried to investigate both NAFLD and IR prevalence in a hospital based population of BCa patients. We studied laboratory data from 204 patients with histologically confirmed non metastatic BCa and 50 subjects with no BCa, but with bladder diseases (no Ca BD). We evaluated the presence of NAFLD by the triglycerides/glucose Index (TyG Index), using a cut-off of 0.59 and by the Aspartate Aminotransferase/Alanine Aminotransferase AST/ALT ratio. IR was assessed by the same TyG Index (cut-off 4.68) and the triglycerides/High-Density Lipoprotein HDL ratio (cut-off 2.197). The diagnosis of impaired fasting glucose (IFG), condition of prediabetes, as well as that of T2DM was assessed according to canonical guidelines. The TyG Index predicted NAFLD presence in both groups (p = 0.000), but the BCa group showed a major percentage of NAFLD cases with respect to no Ca BD group (59% versus 40%). A greater proportion of IR (47%) in BCa group than in no Ca BD one (37%) was evidenced by the TyG Index with its median value significantly different (p = 0.0092). This high rate of IR in the BCa group was confirmed by the triglycerides/HDL ratio (p = 0.02). Prediabetes and T2DM were more prevalent in the BCa group than no Ca BD group (p = 0.024). In this study a consistent NAFLD presence was found in BCa patients. This is an important comorbidity factor that deserves further consideration in prospective studies. The higher prevalence of NAFLD, IR, prediabetes and T2DM in the BCa group evidences the need that these disorders should be reckoned as adjunct factors that could impact on this cancerous disease.

Impact of measured total keratometry versus anterior keratometry on the refractive outcomes of the AT TORBI 709-MP toric intraocular lens

PURPOSE

The aim of this study was to compare the visual and refractive outcomes of total keratometry (TK) versus anterior keratometry (AK) measurements of the IOLMaster 700® (Carl Zeiss Meditec AG, Jena, Germany) in surgery for age-related cataract with preexisting corneal astigmatism.

METHODS

Monocentric retrospective comparative study. The IOLMaster 700® biometer was used in the 2 groups: in AK mode (AK group) and in TK mode (TK group), for toric IOL (AT TORBI 709 MP) calculation with ZCALC®, Zeiss toric IOL calculator. A 2:1 matching was made between the AK and TK groups. Uncorrected distance visual acuity (UDVA), the correction index and the error in predicted residual astigmatism were analyzed 1 month postoperatively using the vector analysis by the Alpins method.

RESULTS

The whole cohort included 405 eyes distributed as follows after 2:1 matching: 158 eyes in the AK group and 79 eyes in the TK group. The mean UDVA was similar in both groups (0.07 ± 0.10 LogMAR; p = 0.587). No significant difference in mean absolute error in predicted residual astigmatism (0.37 ± 0.33 D versus 0.35 ± 0.26 D; p = 0.545) and in mean centroid error in predicted residual astigmatism (0.19 ± 0.49 at 3° and 0.06 ± 0.46 at 0°; p = 0.008 and 0.161 respectively for the x- and y-components) was found between the AK and TK groups.

CONCLUSION

TK of the IOLMaster 700® gives excellent refractive and visual outcomes, comparable to those obtained in AK mode, without showing its superiority for corneas with regular astigmatism.

Predicting dementia diagnosis from cognitive footprints in electronic health records: a case-control study protocol

INTRODUCTION

Dementia is a group of disabling disorders that can be devastating for persons living with it and for their families. Data-informed decision-making strategies to identify individuals at high risk of dementia are essential to facilitate large-scale prevention and early intervention. This population-based case-control study aims to develop and validate a clinical algorithm for predicting dementia diagnosis, based on the cognitive footprint in personal and medical history.

METHODS AND ANALYSIS

We will use territory-wide electronic health records from the Clinical Data Analysis and Reporting System (CDARS) in Hong Kong between 1 January 2001 and 31 December 2018. All individuals who were at least 65 years old by the end of 2018 will be identified from CDARS. A random sample of control individuals who did not receive any diagnosis of dementia will be matched with those who did receive such a diagnosis by age, gender and index date with 1:1 ratio. Exposure to potential protective/risk factors will be included in both conventional logistic regression and machine-learning models. Established risk factors of interest will include diabetes mellitus, midlife hypertension, midlife obesity, depression, head injuries and low education. Exploratory risk factors will include vascular disease, infectious disease and medication. The prediction accuracy of several state-of-the-art machine-learning algorithms will be compared.

ETHICS AND DISSEMINATION

This study was approved by Institutional Review Board of The University of Hong Kong/Hospital Authority Hong Kong West Cluster (UW 18-225). Patients' records are anonymised to protect privacy. Study results will be disseminated through peer-reviewed publications. Codes of the resulted dementia risk prediction algorithm will be made publicly available at the website of the Tools to Inform Policy: Chinese Communities' Action in Response to Dementia project (https://www.tip-card.hku.hk/).

Cellular and molecular mechanisms of IMMunE dysfunction and Recovery from SEpsis-related critical illness in adults: An observational cohort study (IMMERSE) protocol paper

Sepsis is a common illness. Immune responses are considered major drivers of sepsis illness and outcomes. However, there are no proven immunomodulator therapies in sepsis. We hypothesised that in-depth characterisation of sepsis-specific immune trajectory may inform immunomodulation in sepsis-related critical illness. We describe the protocol of the IMMERSE study to address this hypothesis. We include critically ill sepsis patients without documented immune comorbidity and age–sex matched cardiac surgical patients as controls. We plan to perform an in-depth biological characterisation of innate and adaptive immune systems, platelet function, humoral components and transcriptional determinants of the immune system responses in sepsis. This will be done at pre-specified time points during their critical illness to generate an illness trajectory. The sample size for each biological assessment is different and is described in detail. In summary, the overall aim of the IMMERSE study is to increase the granularity of longitudinal immunology model of sepsis to inform future immunomodulation trials.

Association between fasting glucose levels and adhesive capsulitis in a normoglycemic population: a case-control study

BACKGROUND

Hyperglycemia is the most commonly cited risk factor for adhesive capsulitis. However, no study has established whether fasting glucose levels within the normoglycemic range are associated with idiopathic adhesive capsulitis (IAC). This study hypothesized that increments of fasting glucose levels within the normoglycemic range would be linked to IAC. This study investigated any association between normoglycemic fasting glucose levels and IAC.

METHODS

This case-control study comprised a group of 151 patients with IAC without intrinsic shoulder lesions, extrinsic causes, or known metabolic risk factors such as diabetes, dyslipidemia, and thyroid dysfunction. The control group comprised 453 age- and sex-matched persons seeking general check-ups at the authors' health promotion center during the same period as the case group. Control subjects had normal shoulder function, no previous diagnosis of adhesive capsulitis or of metabolic disease, and no history of trauma or of shoulder surgery. The studied variables were body mass index, serum lipid profiles, thyroid hormone levels, fasting glucose levels, glycosylated hemoglobin A1c, and high-sensitivity C-reactive protein. Fasting glucose levels were studied as scale data and categorical data (<85, 85-89, 90-94, and 95-99 mg/dL). Multivariable conditional logistic regression analysis evaluated the matched sets of subjects. Odds ratios and 95% confidence intervals were determined for various potentially associated factors.

RESULTS

Fasting glucose level, hypercholesterolemia, and high-sensitivity C-reactive protein were significantly associated with IAC (P ≤ .030). Fasting glucose levels in the <85 mg/dL quartile were significantly negatively associated with IAC (P ≤ .001). In contrast, fasting glucose levels in the 90-94 mg/dL quartile or higher were significantly positively associated with IAC (P ≤ .034).

CONCLUSION

IAC is positively associated with fasting glucose levels of 90-99 mg/dL, which are currently considered normoglycemic.

Thrombocytopenia and the effect of platelet transfusions on the occurrence of intracranial hemorrhage in patients with acute leukemia - a nested case-control study

We designed a study to describe the incidence of intracranial hemorrhage according to severity and duration of thrombocytopenia and to quantify the associations of platelet transfusions with intracranial hemorrhage in patients with acute leukemia. In this case-control study nested in a cohort of 859 leukemia patients, cases (n = 17) were patients diagnosed with intracranial hemorrhage who were matched with control patients (n = 55). We documented platelet counts and transfusions for seven days before the intracranial hemorrhage in cases and in a “matched” week for control patients. Three measures of platelet count exposure were assessed in four potentially important time periods before hemorrhage. Among these leukemia patients, we observed the cumulative incidence of intracranial hemorrhage of 3.5%. Low platelet counts were, especially in the three to seven days preceding intracranial hemorrhage, associated with the incidence of intracranial hemorrhage, although with wide confidence intervals. Platelet transfusions during the week preceding the hemorrhage were associated with higher incidences of intracranial hemorrhage; rate ratios (95% confidence interval) for one or two platelet transfusions and for more than two transfusions compared with none were 4.04 (0.73 to 22.27) and 8.91 (1.53 to 51.73) respectively. Thus, among acute leukemia patients, the risk of intracranial hemorrhage was higher among patients with low platelet counts and after receiving more platelet transfusions. Especially, the latter is likely due to clinical factors leading to increased transfusion needs.

Association between indoor air pollution, tobacco smoke and tuberculosis: an updated systematic review and meta-analysis

OBJECTIVE

This study aims to further quantify evidence of the association between exposure to indoor air pollution (IAP), tobacco smoke etc., on the one hand and the risk of contracting tuberculosis (TB) on the other.

STUDY DESIGN

This was a systematic review and meta-analysis of articles published between June 2014 and February 2020 in PubMed, Web of Science, among others.

METHODS

We only included studies that controlled for confounders, screened both the exposed and unexposed study participants, and passive smoking studies that limited the study population to non-smokers. Quality of studies was assessed using the Newcastle-Ottawa scale. The analysis was conducted using STATA, and pooled effect sizes were calculated using the random-effects model, and heterogeneity was tested for using the Cochran Q test and I2 statistic.

RESULTS

A total of 26 articles were included in the final analysis. There was an increased risk of contracting TB among people exposed to IAP (risk ratio [RR] = 1.68, 95% confidence interval [CI] 1.108-2.542). We also observed a two-fold increase in the risk of contracting TB from exposure to secondhand tobacco smoke (RR = 2.15, 95%CI 1.419-3.242). Tobacco smoking doubled the risk of contracting TB (RR = 2.67, 95%CI 2.017-3.527). Furthermore, studies that used microbiological tests showed a higher RR compared to those that used other TB diagnostic methods.

CONCLUSION

Exposure to IAP and secondhand tobacco smoke increases the risk of contracting TB. Various disease prevention campaigns should include IAP awareness and encourage a shift to cleaner sources of energy.

Diabetes is associated with familial idiopathic normal pressure hydrocephalus: a case-control comparison with family members

BACKGROUND

The pathophysiological basis of idiopathic normal pressure hydrocephalus (iNPH) is still unclear. Previous studies have shown a familial aggregation and a potential heritability when it comes to iNPH. Our aim was to conduct a novel case-controlled comparison between familial iNPH (fNPH) patients and their elderly relatives, involving multiple different families.

METHODS

Questionnaires and phone interviews were used for collecting the data and categorising the iNPH patients into the familial (fNPH) and the sporadic groups. Identical questionnaires were sent to the relatives of the potential fNPH patients. Venous blood samples were collected for genetic studies. The disease histories of the probable fNPH patients (n = 60) were compared with their ≥ 60-year-old relatives with no iNPH (n = 49). A modified Charlson Comorbidity Index (CCI) was used to measure the overall disease burden. Fisher's exact test (two-tailed), the Mann-Whitney U test (two-tailed) and a multivariate binary logistic regression analysis were used to perform the statistical analyses.

RESULTS

Diabetes (32% vs. 14%, p = 0.043), arterial hypertension (65.0% vs. 43%, p = 0.033), cardiac insufficiency (16% vs. 2%, p = 0.020) and depressive symptoms (32% vs. 8%, p = 0.004) were overrepresented among the probable fNPH patients compared to their non-iNPH relatives. In the age-adjusted multivariate logistic regression analysis, diabetes remained independently associated with fNPH (OR = 3.8, 95% CI 1.1-12.9, p = 0.030).

CONCLUSIONS

Diabetes is associated with fNPH and a possible risk factor for fNPH. Diabetes could contribute to the pathogenesis of iNPH/fNPH, which motivates to further prospective and gene-environmental studies to decipher the disease modelling of iNPH/fNPH.

Lung involvement in macrophage activation syndrome and severe COVID-19: results from a cross-sectional study to assess clinical, laboratory and artificial intelligence-radiological differences

OBJECTIVES

To evaluate the clinical pictures, laboratory tests and imaging of patients with lung involvement, either from severe COVID-19 or macrophage activation syndrome (MAS), in order to assess how similar these two diseases are.

METHODS

The present work has been designed as a cross-sectional single-centre study to compare characteristics of patients with lung involvement either from MAS or severe COVID-19. Chest CT scans were assessed by using an artificial intelligence (AI)-based software.

RESULTS

Ten patients with MAS and 47 patients with severe COVID-19 with lung involvement were assessed. Although all patients showed fever and dyspnoea, patients with MAS were characterised by thrombocytopaenia, whereas patients with severe COVID-19 were characterised by lymphopaenia and neutrophilia. Higher values of H-score characterised patients with MAS when compared with severe COVID-19. AI-reconstructed images of chest CT scan showed that apical, basal, peripheral and bilateral distributions of ground-glass opacities (GGOs), as well as apical consolidations, were more represented in severe COVID-19 than in MAS. C reactive protein directly correlated with GGOs extension in both diseases. Furthermore, lymphopaenia inversely correlated with GGOs extension in severe COVID-19.

CONCLUSIONS

Our data could suggest laboratory and radiological differences between MAS and severe COVID-19, paving the way for further hypotheses to be investigated in future confirmatory studies.

Expedited surgery in geriatric hip fracture patients taking direct oral anticoagulants is not associated with increased short-term complications or mortality rates

Objectives:

The purpose of this study was to evaluate potential differences in time to surgery, bleeding risk, wound complications, length of stay, transfusion rate, and 30-day mortality between patients anticoagulated with direct oral anticoagulants (DOACs) and those not anticoagulated at the time of evaluation for an acute hip fracture.

Design:

Retrospective chart review Level III Study.

Setting:

One university-based hospital in Rochester, NY.

Patients/Intervention

: Patients 65 years and older undergoing operative treatment of a hip fracture over a 5-year period. Chart review identified patients on DOAC therapy at the time of injury as well as an age and sex-matched control group not on anticoagulation.

Main outcome measurements

: Demographics, procedure type, admission/postoperative laboratory work, perioperative metrics, transfusion metrics, discharge course, reoperation, readmission, wound complications, and 30-day mortality were obtained for comparison.

Results:

Thirty-six hip fractures anticoagulated on DOACs were compared to 108 controls. The DOAC group had delays to operative treatment (27.6 h, SD 16.3 h, 95% CL [22.0–33.1]) vs the control group (19.8 h, SD 10.5 h, 95% CL [17.7–21.8], P = .01). No differences were found in estimated blood loss, procedure time, or change in hemoglobin. Transfusion rates were not significantly different between groups (58.3% DOAC vs 47.2% control, P = .25). No difference in reoperation, readmission, wound complication, deep venous thrombosis rates, or 30-day mortality rates were found.

Conclusion:

Patients presenting on DOAC therapy at the time of hip fracture have a delay to surgery compared with age and sex-matched controls, but no increase in short term complications or mortality rates. Expedited surgery (within 48 h) appeared to be safe and effective treatment for hip fracture patients on DOAC therapies.

Risk factors for bleeding in haemato-oncology patients-a nested case-control study: The BITE study protocol (Bleeding In Thrombocytopenia Explained)

INTRODUCTION

Haemato-oncological patients often receive platelet count driven prophylactic platelet transfusions to prevent bleeding. However, many prophylactically transfused patients still bleed. More knowledge on risk factors for bleeding is therefore needed. This will enable identification of bleeding risk profiles on which future transfusion policy can be optimised. The present BITE study (Bleeding In Thrombocytopenia Explained) aims to identify clinical conditions and biomarkers that are associated with clinically relevant bleeding events.

METHODS AND ANALYSIS

A matched case-control study nested in a cohort of haemato-oncological patients in the Netherlands. We collect a limited number of variables from all eligible patients, who together form the source population. These patients are followed for the occurrence of clinically relevant bleeding. Consenting patients of the source population form the cohort. Cases from the cohort are frequency matched to selected control patients for the nested case-control study. Of both case and control patients more detailed clinical data is collected.

STUDY POPULATION

Adult haemato-oncological patients, who are admitted for intensive chemotherapeutic treatment or stem cell transplantation, or who received such treatments in the past and are readmitted for disease or treatment-related adverse events.

STATISTICAL ANALYSIS

Bleeding incidences will be calculated for the total source population, as well as for different subgroups. The association between potential risk factors and the occurrence of bleeding will be analysed using conditional logistic regression, to account for matching of case and control patients.

ETHICS AND DISSEMINATION

The study was approved by the Medical Research Ethics Committee Leiden Den Haag and Delft, and the Radboudumc Committee on Research Involving Human Subjects. Approval in seven other centres is foreseen. Patients will be asked for written informed consent and data is coded before analyses, according to Dutch privacy law. Results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NL62499.058.17. NCT03505086; Pre-results.

Misleading Epidemiological and Statistical Evidence in the Presence of Simpson's Paradox: An Illustrative Study Using Simulated Scenarios of Observational Study Designs

This study empirically illustrates the mechanism by which epidemiological effect measures and statistical evidence can be misleading in the presence of Simpson's paradox and identify possible alternative methods of analysis to manage the paradox.

Three scenarios of observational study designs, including cross-sectional, cohort, and case-control approaches, are simulated. In each scenario, data are generated, and various methods of epidemiological and statistical analyses are undertaken to obtain empirical results that illustrate Simpson's paradox and mislead conclusions. Rational methods of analysis are also performed to illustrate how to avoid pitfalls and obtain valid results.

In the presence of Simpson's paradox, results from analyses in overall data contradict the findings from all subgroups of the same data. This paradox occurs when distributions of confounding characteristics are unequal in the groups being compared. Data analysis methods which do not take confounding factor into account, including epidemiological 2×2 table analysis, independent samples t-test, Wilcoxon rank-sum test, chi-square test, and univariable regression analysis, cannot manage the problem of Simpson's paradox and mislead research conclusions. Mantel-Haenszel procedure and multivariable regression methods are examples of rational analysis methods leading to valid results.

Therefore, Simpson's paradox arises as a consequence of extreme unequal distributions of a specific inherent characteristic in groups being compared. Analytical methods which take control of confounding effect must be applied to manage the paradox and obtain valid research evidence regarding the causal association.

Comparison of the predictive validity of three fall risk assessment tools and analysis of fall-risk factors at a tertiary teaching hospital

AIMS AND OBJECTIVES

The main purpose of this study was to identify the best fall-risk assessment tool, among the Morse Fall Scale, the Johns Hopkins fall-risk Assessment Tool and the Hendrich II fall-risk Model, for a tertiary teaching hospital. The study also analysed fall-risk factors in the hospital, focusing on the items of each fall assessment tool.

METHODS

Data on falls were obtained from the patient safety reports and electronic nursing records of a tertiary teaching hospital. A retrospective study was conducted to compare the sensitivity, specificity, area under the curve, positive predictive value, negative predictive value, Youden index and accuracy of the Morse Fall Scale, the Johns Hopkins fall-risk Assessment Tool and the Hendrich II fall-risk Model. This study was conducted according to the Strengthening the Reporting of Observational Studies in Epidemiology guideline for reporting case-control studies.

RESULTS

By analysing the association between falls and the items included in the three tools, we identified significant fall-risk factors such as gait, dizziness or vertigo, changes in mental status, impulsivity, history of falling, elimination disorder, drugs affecting falls, and depression.

CONCLUSIONS

The Hendrich II fall-risk Model had the best predictive performance for falls of the three tools, considering the highest in the area under the curve and the Youden index that comprehensively analysed sensitivity and specificity, while the Johns Hopkins fall-risk Assessment Tool had the highest accuracy. The most significant fall-risk predictors are gait, dizziness or vertigo, change in mental state, and history of falling.

RELEVANCE TO CLINICAL PRACTICE

To improve the fall assessment performance of the Morse Fall Scale at the study hospital, we propose that it be supplemented with four most significant fall-risk predictors identified in this study.

Precision Diagnostics by Affinity-Mass Spectrometry: A Novel Approach for Fetal Growth Restriction Screening During Pregnancy

Fetal growth restriction (FGR) affects about 3% to 8% of pregnancies, leading to higher perinatal mortality and morbidity. Current strategies for detecting fetal growth impairment are based on ultrasound inspections. However, antenatal detection rates are insufficient and critical in countries with substandard care. To overcome difficulties with detection and to better discriminate between high risk FGR and low risk small for gestational age (SGA) fetuses, we investigated the suitability of risk assessment based on the analysis of a recently developed proteome profile derived from maternal serum in different study groups. Maternal serum, collected at around 31 weeks of gestation, was analyzed in 30 FGR, 15 SGA, and 30 control (CTRL) pregnant women who delivered between 31 and 40 weeks of gestation. From the 75 pregnant women of this study, 2 were excluded because of deficient raw data and 2 patients could not be grouped due to indeterminate results. Consistency between proteome profile and sonography results was obtained for 59 patients (26 true positive and 33 true negative). Of the proteome profiling 12 contrarious grouped individuals, 3 were false negative and 9 were false positive cases with respect to ultrasound data. Both true positive and false positive grouping transfer the respective patients to closer surveillance and thorough pregnancy management. Accuracy of the test is considered high with an area-under-curve value of 0.88 in receiver-operator-characteristics analysis. Proteome profiling by affinity-mass spectrometry during pregnancy provides a reliable method for risk assessment of impaired development in fetuses and consumes just minute volumes of maternal peripheral blood. In addition to clinical testing proteome profiling by affinity-mass spectrometry may improve risk assessment, referring pregnant women to specialists early, thereby improving perinatal outcomes.

Association Between High-Sensitivity C-Reactive Protein and Idiopathic Adhesive Capsulitis

BACKGROUND

Chronic inflammation is implicated in the development of idiopathic adhesive capsulitis (IAC), whose association with high-sensitivity C-reactive protein (CRP), an inflammation marker, is undetermined. This study's purposes were to investigate the association between high-sensitivity CRP levels and IAC and to determine the metabolic factors associated with high-sensitivity CRP.

METHODS

This case-control study examined a group of 202 patients with IAC and without intrinsic shoulder lesions or extrinsic causes and a control group of 606 age and sex-matched persons seeking general check-ups at our health promotion center during the same period as the case group. Control subjects had normal shoulder function and no previously diagnosed adhesive capsulitis; no medication for diabetes, dyslipidemia, and thyroid abnormalities; and no history of trauma or of shoulder surgery. The studied variables were body mass index; diabetes; thyroid abnormalities; dyslipidemias; triglyceride/high-density lipoprotein (TG/HDL) >3.5; serum levels of thyroid hormone, fasting glucose, and glycosylated hemoglobin A1c (HbA1c); and high-sensitivity CRP >1.0 mg/L. Multivariable conditional logistic regression analysis evaluated the matched sets of subjects. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for the studied variables possibly affecting IAC.

RESULTS

Serum high-sensitivity CRP >1.0 mg/L was significantly associated with IAC (OR, 2.47 [95% CI, 1.65 to 3.70]) after adjusting for diabetes, fasting glucose level, HbA1c, dyslipidemia, TG/HDL >3.5, and thyroid-stimulating hormone (p ≤ 0.031). Diabetes (OR, 1.71 [95% CI, 1.09 to 3.33]), fasting glucose level (OR, 1.54 [95% CI, 1.12 to 2.12]), HbA1c (OR, 2.00 [95% CI, 1.25 to 3.22]), hypertriglyceridemia (OR, 1.70 [95% CI, 1.03 to 3.41]), hypo-high-density lipoproteinemia (OR, 1.98 [95% CI, 1.04 to 3.79]), and TG/HDL >3.5 (OR, 1.37 [95% CI, 1.06 to 1.88]) were significantly associated with high-sensitivity CRP >1.0 mg/L in patients with IAC (p ≤ 0.039).

CONCLUSIONS

Serum high-sensitivity CRP >1.0 mg/L is an independent associated marker for IAC. Dyslipidemia, insulin resistance, and hyperglycemia, which are recognized factors associated with IAC, are also associated with high-sensitivity CRP >1.0 mg/L in these patients, supporting the interaction of chronic systemic inflammation in IAC.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Associations among gastroesophageal reflux disease, mental disorders, sleep and chronic temporomandibular disorder: a case-control study

BACKGROUND

Temporomandibular disorders (TMDs) are a family of pain-related disorders associated with impaired function in the jaw, temporomandibular joint and muscles of mastication. Our objectives were to evaluate the association between chronic TMD and gastresophageal reflux disease (GERD) and to determine whether mental disorders or undermined sleep mediates this association.

METHODS

We conducted a case-control study involving 1522 consecutive adult patients with chronic TMD and 1522 matched controls from 2 hospitals in China. All participants were aged between 18 and 70 years and were recruited from July 2017 to April 2018 Chronic TMD was diagnosed by trained dentists using the criteria in the Orofacial Pain Prospective Evaluation and Risk Assessment Study. Trained gastroenterologists made blinded diagnoses of GERD according to the Montreal definition and classification (at least 2 d of mild symptoms, or 1 d of moderate or severe symptoms per week). We used validated questionnaires to evaluate psychological status and sleep quality.

RESULTS

Of the study participants, we identified 132 patients and 61 controls with GERD. Using conditional logistic regression analysis, we identified GERD as a risk factor for TMD (odds ratio 2.74, 95% confidence interval 1.88 to 3.98). Mediation analyses identified that somatization, anxiety and undermined sleep moderately mediated the relation between TMD and GERD.

INTERPRETATION

Our study suggests that symptomatic GERD is associated with chronic, painful TMD, and somatization, anxiety and undermined sleep mediate this association to a certain extent. Due consideration should be given to the evaluation and management of gastrointestinal symptoms and mental disorders in the combined therapy for painful TMD.

The association of smoking and socioeconomic status on cutaneous melanoma: a population-based, data-linkage, case-control study

BACKGROUND

Previous studies have identified an inverse association between melanoma and smoking; however, data from population-based studies are scarce.

OBJECTIVES

To determine the association between smoking and socioeconomic (SES) on the risk of development of melanoma. Furthermore, we sought to determine the implications of smoking and SES on survival.

METHODS

We conducted a population-based case-control study. Cases were identified from the Welsh Cancer Intelligence and Surveillance Unit (WCISU) during 2000-2015 and controls from the general population. Smoking and SES were obtained from data linkage with other national databases. The association of smoking status and SES on the incidence of melanoma were assessed using binary logistic regression. Multivariate survival analysis was performed on a melanoma cohort using a Cox proportional hazard model using survival as the outcome.

RESULTS

During 2000-2015, 9636 patients developed melanoma. Smoking data were obtained for 7124 (73·9%) of these patients. There were 26 408 controls identified from the general population. Smoking was inversely associated with melanoma incidence [odds ratio (OR) 0·70, 95% confidence interval (CI) 0·65-0·76]. Smoking was associated with an increased overall mortality [hazard ratio (HR) 1·30, 95% CI 1·09-1·55], but not associated with melanoma-specific mortality. Patients with higher SES had an increased association with melanoma incidence (OR 1·58, 95% CI 1·44-1·73). Higher SES was associated with an increased chance of both overall (HR 0·67, 95% CI 0·56-0·81) and disease-specific survival (HR 0·69, 95% CI 0·53-0·90).

CONCLUSIONS

Our study has demonstrated that smoking appeared to be associated with reduced incidence of melanoma. Although smoking increases overall mortality, no association was observed with melanoma-specific mortality. Further work is required to determine if there is a biological mechanism underlying this relationship or an alternative explanation, such as survival bias. What's already known about this topic? Previous studies have been contradictory with both negative and positive associations between smoking and the incidence of melanoma reported. Previous studies have either been limited by publication bias because of selective reporting or underpowered. What does this study add? Our large study identified an inverse association between smoking status and melanoma incidence. Although smoking status was negatively associated with overall disease survival, no significant association was noted in melanoma-specific survival. Socioeconomic status remains closely associated with melanoma. Although higher socioeconomic populations are more likely to develop the disease, patients with lower socioeconomic status continue to have a worse prognosis.

Quasispecies characteristic in "a" determinant region is a potential predictor for the risk of immunoprophylaxis failure of mother-to-child-transmission of sub-genotype C2 hepatitis B virus: a prospective nested case-control study

OBJECTIVE

This study was performed to explore the correlation between the characteristics of hepatitis B virus (HBV) quasispecies in HBV-infected pregnant women and the risk of immunoprophylaxis failure for their infants.

DESIGN

In this prospective nested case-control study, the characteristics of HBV quasispecies in mothers whose infants were immunoprophylaxis success (control group) and those whose infants were immunoprophylaxis failure (case group) were analysed by the clone-based sequencing of full-length HBV genome and next-generation sequencing (NGS) of "a" determinant region, and were compared between the two groups.

RESULTS

The quasispecies characteristics including mutant frequency, Shannon entropy and mean genetic distance at amino acid level of "a" determinant region were significantly lower in case group than that in control group, using the full-length HBV genome clone-based sequencing assay. These results were confirmed by NGS assay. Notably, we discovered that the differences were also significant at nucleotide level by NGS assay. Furthermore, the risk of immunoprophylaxis failure could be predicted by analysing the three HBV quasispecies characteristics either at nucleotide level or at amino acid level of "a" determinant region, and the corresponding predictive values were tentatively set up.

CONCLUSIONS

HBV quasispecies with a more complex mutant spectrum in "a" determinant region might be more vulnerable to extinct through mother-to-child-transmission (MTCT). More importantly, analysing HBV quasispecies characteristics in pregnant women with high HBV DNA load might be helpful to predict the high-risk population of immunoprophylaxis failure, and consequently provide accurate intervention against MTCT of HBV.

Role of psychiatric, cardiovascular, socioeconomic, and demographic risk factors on idiopathic normal pressure hydrocephalus: A retrospective case-control study

OBJECTIVES

Currently, predicting and preventing idiopathic normal pressure hydrocephalus (iNPH) remains challenging, especially for patients without a history of cerebrovascular disease. By exploring the role of cardiovascular and psychiatric history, demographics, and socioeconomic status in iNPH, will provide better direction for elucidating the etiology or addressing healthcare inequalities.

PATIENTS AND METHODS

To investigate iNPH with respect to the selected risk factors, we conducted a retrospective case-control study from a neuroscience institute in Hawaii with a patient pool of 25,843. After excluding patients with a history of cerebrovascular disease, we identified 29 cases which meet the American-European guidelines for iNPH diagnosis. Meanwhile, 116 controls matched to age, sex, and race were also randomly selected.

RESULTS

Median age at diagnosis was 83 (IQR: 74-88), with cases estimated 22 years older than controls (95 % CI: 14.00-29.00; p = 0.0000001). Patients with iNPH were more likely to be White (OR 4.01, 95 % CI: 1.59-10.11; p = 0.0042) and less likely Native Hawaiian and other Pacific Islander (OR 0.010, 95 % CI: 0.00-0.78; p = 0.014). Median household income was $2874 (95 % CI: 0.000089-6905; p = 0.088) greater amongst iNPH cases. Effect size amongst cardiovascular risk factors was not found statistically significant (i.e., body mass index, hyperlipidemia, type 2 diabetes mellitus, hypertension, coronary artery disease or prior myocardial infarction history, peripheral vascular disease, smoking status, congestive heart failure, atrial fibrillation/flutter, and history of prosthetic valve replacement). However, iNPH patients were more likely to have a history of alcohol use disorder (OR 8.29, 95 % CI: 0.99-453.87; p = 0.050) and history of a psychiatric disorder (OR 2.48; 95 % CI: 1.08-5.68; p = 0.029). Odds ratio for autoimmune disorder, thyroid disorder, glaucoma, and seizures did not reach statistical significance.

CONCLUSION

Patient race (i.e., White; Native Hawaiian or other Pacific Islander) was found associated with iNPH development. Meanwhile, after excluding those with cerebrovascular disease, cardiovascular risk factors were not found associated with iNPH. Lastly, iNPH cases were more inclined to have a history of alcohol use disorder and prior psychiatric disorder. Overall, this data reveals that a racial disparity exists amongst iNPH, as well as highlights the role of various cardiovascular and psychiatric risk factors, which can potentially provide direction in etiology elucidation.

Protection of wetlands as a strategy for reducing the spread of avian influenza from migratory waterfowl

Highly pathogenic avian influenza (HPAI) H5N1 has led to the death or destruction of millions of domesticated and wild birds and caused hundreds of human deaths worldwide. As with other HPAIs, H5N1 outbreaks among poultry have generally been caused by contact with infected migratory waterfowl at the interface of wildlands and human-dominated landscapes. Using a case-control epidemiological approach, we analyzed the relation between habitat protection and H5N1 outbreaks in China from 2004 to 2017. We found that while proximity to unprotected waterfowl habitats and rice paddy generally increased outbreak risk, proximity to the most highly protected habitats (e.g., Ramsar-designated lakes and wetlands) had the opposite effect. Protection likely involves two mechanisms: the separation of wild waterfowl and poultry populations and the diversion of wild waterfowl from human-dominated landscapes toward protected natural habitats. Wetland protection could therefore be an effective means to control avian influenza while also contributing to avian conservation.

Are food exposures obtained through commercial market panels representative of the general population? Implications for outbreak investigations

Current methods of control recruitment for case-control studies can be slow (a particular issue for outbreak investigations), resource-intensive and subject to a range of biases. Commercial market panels are a potential source of rapidly recruited controls. Our study evaluated food exposure data from these panel controls, compared with an established reference dataset. Market panel data were collected from two companies using retrospective internet-based surveys; these were compared with reference data from the National Diet and Nutrition Survey (NDNS). We used logistic regression to calculate adjusted odds ratios to compare exposure to each of the 71 food items between the market panel and NDNS participants. We compared 2103 panel controls with 2696 reference participants. Adjusted for socio-demographic factors, exposure to 90% of foods was statistically different between both panels and the reference data. However, these differences were likely to be of limited practical importance for 89% of Panel A foods and 79% of Panel B foods. Market panel food exposures were comparable with reference data for common food exposures but more likely to be different for uncommon exposures. This approach should be considered for outbreak investigation, in conjunction with other considerations such as population at risk, timeliness of response and study resources.

Maternal and health service predictors of postpartum hemorrhage across 14 district, general and regional hospitals in Thailand

Background

Postpartum hemorrhage (PPH) is a preventable complication, however, it remains being the leading cause of maternal mortality and morbidity worldwide including Thailand.

Methods

A case-control study to examine the risk factors associated with PPH across the hospitals under the Ministry of Public Health in Thailand, was conducted. A total of 1833 patient birth records and hospital profiles including human and physical resources from 14 hospitals were obtained. A multiple logistic regression was used identifing the factors that are significantly associated with PPH.

Results

The results show that the rate of PPH varied across the hospitals ranging from 1.4 to 10.6%. Women with past history of PPH were more likely to have increased risk of having PPH by 10.97 times (95% CI 2.27,53.05) compared to those who did not. The odds of PPH was higher in district and general hospitals by 14 (95% CI 3.95,50.04) and 7 (95% CI 2.27,23.27) times respectively, compared to regional hospitals. The hospitals which had inadequate nurse midwife to patient ratio (OR 2.31,95% CI 1.08,4.92), lacked nurse midwives with working experience of 6–10 years (OR 2.35, 95% CI 1.41,3.92), as well as inadequate equipment and supplies for emergency obstetric care (OR 6.47, 95% CI 1.93,21.63), had significantly higher incidence of having PPH, respectively.

Conclusions

This study provides interesting information that the rate of PPH varies across the hospitals in Thailand, in particular where essential nurse midwives, equipment, and supplies are limited. Therefore, improving health care services by allocating sufficient human and physical resources would contribute to significantly reduce this complication.

Harnessing cell-free DNA: plasma circulating tumour DNA for liquid biopsy in genitourinary cancers

In the era of precision oncology, liquid biopsy techniques, especially the use of plasma circulating tumour DNA (ctDNA) analysis, represent a paradigm shift in the use of genomic biomarkers with considerable implications for clinical practice. Compared with tissue-based tumour DNA analysis, plasma ctDNA is more convenient to test, more readily accessible, faster to obtain and less invasive, minimizing procedure-related risks and offering the opportunity to perform serial monitoring. Additionally, genomic profiles of ctDNA have been shown to reflect tumour heterogeneity, which has important implications for the identification of resistant clones and selection of targeted therapy well before clinical and radiographic changes occur. Moreover, plasma ctDNA testing can also be applied to cancer screening, risk stratification and quantification of minimal residual disease. These features provide an unprecedented opportunity for early treatment of patients, improving the chances of treatment success.

SGLT2 Inhibitors and the Risk of Hospitalization for Fournier's Gangrene: A Nested Case-Control Study

INTRODUCTION

Based on post-marketing surveillance, concern has been raised that sodium-glucose cotransporter 2 inhibitors (SGLT2i) may increase the risk of necrotizing fasciitis of the perineum (Fournier's gangrene, FG). As a result of the low incidence of FG, data from clinical trials may be insufficient to robustly assess this issue because of the relatively limited numbers of participants. Real-world evidence may help clarify the association between SGLT2i and FG in the type 2 diabetes (T2D) population.

METHODS

A nested case-control study was performed using Truven Health MarketScan™ databases. Each patient with T2D hospitalized for FG between 1 April 2013 (when the first SGLT2i was available) and 31 March 2018 (latest available data) was matched (on the basis of sex, age, and cohort entry date) with six controls from the same cohort. The adjusted odds ratio (OR) of hospitalization for FG was estimated for patients receiving SGLT2i compared with those receiving two or more non-SGLT2i antihyperglycemic agents (AHAs) or insulin alone using conditional logistic regression.

RESULTS

The cohort included 1,897,935 patients, with 216 hospitalized for FG (incidence rate, 5.2 events per 100,000 person-years). Patients with FG ranged from 23 to 79 years of age; 201 (93.1%) were men. Among the 216 FG cases, 9 (4.2%) were current SGLT2i users; among the 1296 matched controls, 100 (7.7%) were current SGLT2i users. Approximately 93% of SGLT2i were used in combination. The adjusted OR of FG in patients treated with SGLT2i compared with patients treated with two or more non-SGLT2i AHAs or insulin alone was 0.55 [95% CI 0.25-1.18].

CONCLUSION

The study did not find that treatment with SGLT2i, as compared with treatment with two or more non-SGLT2i AHAs or insulin alone, was statistically significantly associated with an increased risk of hospitalization for FG. Additional studies are needed to corroborate the findings.

Survival in Living Kidney Donors: An Australian and New Zealand Cohort Study Using Data Linkage

Supplemental Digital Content is available in the text.

Background.

Living kidney donors are a highly selected healthy population expected to have high survival postdonation, but mortality studies are limited. Our study aimed to compare mortality in living kidney donors with the general population in Australia and New Zealand, hypothesizing that donor survival would exceed average survival.

Methods.

All living kidney donors in Australia, 2004–2013, and New Zealand, 2004–2012, from the Australian and New Zealand Living Kidney Donor Registry were included. We ascertained primary cause of death from data linkage with national death registers. Standardized mortality ratios and relative survival were estimated, matching on age, sex, calendar year, and country.

Results.

Among 3253 living kidney donors, there were 32 deaths over 20 331 person-years, with median follow-up 6.2 years [interquartile range: 3.9–8.4]. Only 25 donors had diabetes-fasting blood sugar level predonation, of which 3 had impaired glucose tolerance. At discharge, the median creatinine was 108 µmol/L and estimated glomerular filtration rate was 58 mL/min/1.72 m². Four deaths occurred in the first year: 2 from immediate complications of donation, and 2 from unrelated accidental causes. The leading cause of death was cancer (n = 16). The crude mortality rate was 157 (95% confidence interval [CI], 111-222)/100 000 person-y, and the standardized mortality ratio was 0.33 (95% CI, 0.24-0.47). The 5-year cumulative relative survival was 1.019 (95% CI, 1.014-1.021), confirming that the survival probability in living kidney donors was 2% higher relative to the general population.

Conclusions.

As expected, mortality in living kidney donors was substantially lower than the general population and is reassuring for potential donor counseling. The Living Donor Registry only captured a third of the deaths, highlighting the benefit of data linkage to national death registries in the long-term follow-up of living kidney donors.

The relationship between patient factors and the refusal of analgesics in adult Emergency Department patients with extremity injuries, a case-control study

Background and aims Previous studies have described the phenomenon of oligo-analgesia in Emergency Department patients with traumatic injuries, despite the high prevalence of pain among these patients. Besides aspects related to health care staff, patient related factors might also play a role in suboptimal pain treatment, however evidence is scarce. Therefore, the objective of the current study was to evaluate patient related factors in adult patients refusing offered analgesics during an Emergency Department presentation with extremity injuries. Methods This was a case control study in the Emergency Department of a level 1 Trauma Centre. Cases were defined as adult patients with an extremity injury who declined analgesia, when offered. They were matched to controls from the same population, who accepted analgesics, in a 1:2 ratio using gender as matching variable. Primary outcome was difference in NRS pain score. Secondary outcomes were the relationship between categorical severity of pain scores and refusal of analgesics, exploration of independent predictors of analgesia refusal utilizing multivariate logistic regression and the evaluation of eight beliefs among patients who refuse analgesics. Results Between August 1st and 31st 2016, a total of 253 patients were eligible for inclusion of whom 55 declined analgesic treatment. They were included as cases and matched to 110 controls. Difference in median NRS pain score was significant between the groups: 5.0 (IQR 3.0-8.0) vs. 8.0 (IQR 6.0-9.0), respectively (p < 0.01). Nearly 20% of patients with severe pain declined analgesics, compared to 41% with moderate and 69% with mild pain (p < 0.01). The NRS pain score was the only independent predictor of refusal of analgesic treatment with a mean Odds Ratio of 0.67 (95%-CI 0.54-0.83). Most common patients' beliefs were that pain medication should be used in extreme pain only, fear of decreasing the doctor's ability to judge the injury and fear of addiction to analgesics. Conclusions Pain severity is the single independent predictor of refusal of analgesia, however the following patient beliefs are important as well: pain medication should be used in extreme pain only; fear of decreasing the doctor's ability to judge the injury and the fear of becoming addicted to pain medication. Implications In case patients refuse offered analgesics, the health care provider should actively address patient beliefs that might exist and lead to suboptimal pain treatment.

ABO blood group and risk of newly diagnosed nonalcoholic fatty liver disease: A case-control study in Han Chinese population

Background

ABO blood group has been associated with cardiovascular disease and cancer. However, whether ABO blood group is associated with nonalcoholic fatty liver disease (NAFLD) remains unknown. The present study aimed to clarify this issue.

Methods

A hospital-based case-control study was performed in southwestern China. A total of 583 newly ultrasound-diagnosed NAFLD cases and 2068 controls were included. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of developing NAFLD were calculated by multivariate logistic regression. A propensity score was developed for adjustment and matching.

Results

The proportions of blood groups A, B, AB and O were 31%, 26%, 8% and 35%, respectively. Non-O blood groups were found to be significantly associated with an increased risk of NAFLD (the fully adjusted OR = 1.51, 95% CI: 1.19, 1.91); moreover, compared with blood group O, the fully adjusted ORs of developing NAFLD were 1.50 (95% CI: 1.13, 1.99) for blood group A, 1.59 (95% CI: 1.19, 2.14) for blood group B, and 1.37 (95% CI: 0.86, 2.18) for blood group AB. Similar results were obtained in both propensity-score-adjusted and propensity-score-matched analyses. No evidence of significant effect modification for the association of ABO blood group with the risk of NAFLD was found (all P_interaction>0.05).

Conclusions

Non-O blood groups are significantly associated with an increased risk of NAFLD. Our findings provide some epidemiological evidence for a possible role of ABO glycosyltransferase in the pathogenesis of NAFLD. However, these findings need to be validated by future studies.

Mortality risk and causes of death in patients with non-cystic fibrosis bronchiectasis

BACKGROUND

All-cause mortality risk and causes of death in bronchiectasis patients have not been fully investigated. The aim of this study was to compare the mortality risk and causes of death between individuals with bronchiectasis and those without bronchiectasis.

METHODS

Patients with or without bronchiectasis determined based on chest computed tomography (CT) at one centre between 2005 and 2016 were enrolled. Among the patients without bronchiectasis, a control group was selected after applying additional exclusion criteria. We compared the mortality risk and causes of death between the bronchiectasis and control groups without lung disease. Subgroup analyses were also performed according to identification of Pseudomonas or non-tuberculous mycobacteria, airflow limitation, and smoking status.

RESULTS

Of the total 217,702 patients who underwent chest CT, 18,134 bronchiectasis patients and 90,313 non-bronchiectasis patients were included. The all-cause mortality rate in the bronchiectasis group was 1608.8 per 100,000 person-years (95% confidence interval (CI), 1531.5-1690.0), which was higher than that in the control group (133.5 per 100,000 person-years; 95% CI, 124.1-143.8; P < 0.001). The bronchiectasis group had higher all-cause (adjusted hazard ratio (aHR), 1.26; 95% CI, 1.09-1.47), respiratory (aHR, 3.49; 95% CI, 2.21-5.51), and lung cancer-related (aHR, 3.48; 95% CI, 2.33-5.22) mortality risks than the control group. In subgroup analysis, patients with airflow limitation and ever smokers showed higher all-cause mortality risk among bronchiectasis patients. Therefore, we observed significant interrelation between bronchiectasis and smoking, concerning the risks of all-cause mortality (P for multiplicative interaction, 0.030, RERI, 0.432; 95% CI, 0.097-0.769) and lung cancer-related mortality (RERI, 8.68; 95% CI, 1.631-15.736).

CONCLUSION

Individuals with bronchiectasis had a higher risk of all-cause, respiratory, and lung cancer-related mortality compared to control group. The risk of all-cause mortality was more prominent in those with airflow limitation and in ever smokers.

Risk Factors, Etiologies, and Screening Tools for Sepsis in Pregnant Women: A Multicenter Case-Control Study

BACKGROUND

Given the significant morbidity and mortality of maternal sepsis, early identification is key to improve outcomes. This study aims to evaluate the performance characteristics of the systemic inflammatory response syndrome (SIRS), quick Sequential [Sepsis-related] Organ Failure Assessment (qSOFA), and maternal early warning (MEW) criteria for identifying cases of impending sepsis in parturients. The secondary objective of this study is to identify etiologies and risk factors for maternal sepsis and to assess timing of antibiotics in patients diagnosed with sepsis.

METHODS

Validated maternal sepsis cases during the delivery hospitalization from 1995 to 2012 were retrospectively identified at 7 academic medical centers in the United States and Israel. Control patients were matched by date of delivery in a 1:4 ratio. The sensitivity and specificity of SIRS, qSOFA, and MEW criteria for identifying sepsis were calculated. Data including potential risk factors, vital signs, laboratory values, and clinical management were collected for cases and controls.

RESULTS

Eighty-two sepsis cases during the delivery hospitalization were identified and matched to 328 controls. The most common causes of sepsis were the following: chorioamnionitis 20 (24.4%), endometritis 19 (23.2%), and pneumonia 9 (11.0%). Escherichia coli 12 (14.6%), other Gram-negative rods 8 (9.8%), and group A Streptococcus 6 (7.3%) were the most commonly found pathogens. The sensitivities and specificities for meeting criteria for screening tools were as follows: (1) SIRS (0.93, 0.63); (2) qSOFA (0.50, 0.95); and (3) MEW criteria for identifying sepsis (0.82, 0.87). Of 82 women with sepsis, 10 (12.2%) died. The mortality rate for those who received antibiotics within 1 hour of diagnosis was 8.3%. The mortality rate was 20% for the patients who received antibiotics after >1 hour.

CONCLUSIONS

Chorioamnionitis and endometritis were the most common causes of sepsis, together accounting for about half of cases. Notable differences were observed in the sensitivity and specificity of sepsis screening tools with the highest to lowest sensitivity being SIRS, MEW, and qSOFA criteria, and the highest to lowest specificity being qSOFA, MEW, and SIRS. Mortality was doubled in the cohort of patients who received antibiotics after >1 hour. Clinicians need to be vigilant to identify cases of peripartum sepsis early in its course and prioritize timely antibiotic therapy.

Social relations and presence of others predict bystander intervention: Evidence from violent incidents captured on CCTV

Are individuals willing to intervene in public violence? Half a century of research on the “bystander effect” suggests that the more bystanders present at an emergency, the less likely each of them is to provide help. However, recent meta‐analytical evidence questions whether this effect generalizes to violent emergencies. Besides the number of bystanders present, an alternative line of research suggests that pre‐existing social relations between bystanders and conflict participants are important for explaining whether bystanders provide help. The current paper offers a rare comparison of both factors—social relations and the number of bystanders present—as predictors of bystander intervention in real‐life violent emergencies. We systematically observed the behavior of 764 bystanders across 81 violent incidents recorded by surveillance cameras in Copenhagen, Denmark. Bystanders were sampled with a case–control design, their behavior was observed and coded, and the probability of intervention was estimated with multilevel regression analyses. The results confirm our predicted association between social relations and intervention. However, rather than the expected reversed bystander effect, we found a classical bystander effect, as bystanders were less likely to intervene with increasing bystander presence. The effect of social relations on intervention was larger in magnitude than the effect of the number of bystanders. We assess these findings in light of recent discussions about the influence of group size and social relations in human helping. Further, we discuss the utility of video data for the assessment of real‐life bystander behavior.

Enhancing research quality of studies on VEMPs in central neurological disorders: a scoping review

Common pitfalls in vestibular-evoked myogenic potential (VEMP) recording methods have been extensively outlined by several reviews. Conversely, the robustness of research methodology employed for the design and conduct of VEMP studies has never been appraised. To fill this void, we conducted a scoping review to map and evaluate the overall quality of the existing literature on VEMPs in central neurological disorders. Five databases were searched from inception to October 2018 for case-control studies on multiple sclerosis (MS), cerebellar and/or brainstem strokes, Parkinson's disease (PD), migraine, and tumors of the cerebellopontine angle. Study quality was assessed using the Agency for Healthcare Research and Quality criteria (AHRQ). The 11-criteria AHRQ scoring system revealed that PD studies achieved a score of 5/11, migraine and cerebellar and/or brainstem stroke a score of 4/11, MS and tumors of the cerebellopontine angle a score of 3/11. Age was found to be one of the main sources of case-control imbalance: compared with controls, cases were significantly older with a 3.6-yr difference in MS studies, 6 yr in PD, up to 12 yr in stroke and tumors. Regardless of pathological condition, case-control groups were found unmatched also by gender. Post hoc power calculations revealed that 53% of the studies achieved the minimum statistical power of 80%. This scoping review revealed low research quality across the literature on VEMPs in central neurological disorders. Scoping lines are provided on actions to be undertaken in future studies to establish a common methodological platform and enhance the quality of research in this field.NEW & NOTEWORTHY Robust methodology is a prerequisite for any type of research, particularly for observational designs such as those employed in vestibular-evoked myogenic potential (VEMP) research. On these premises, this scoping review provides methodological guidelines to improve validity, accuracy and consistency of clinical outcomes from VEMP studies involving central nervous system disorders. In fact, the high risk for bias that is inherent to poor methodology threatens the validity of the findings of works that are technically sound but methodologically flawed.

Assessing crash risk considering vehicle interactions with trucks using point detector data

Trucks have distinct driving characteristics in general traffic streams such as lower speeds and limitations in acceleration and deceleration. As a consequence, vehicles keep longer headways or frequently change lane when they follow a truck, which is expected to increase crash risk. This study introduces several traffic measures at the individual vehicle level to capture vehicle interactions between trucks and non-trucks and analyzed how the measures affect crash risk under different traffic conditions. The traffic measures were developed using headways obtained from Inductive Loop Detectors (ILDs). In addition, a truck detection algorithm using a Gaussian Mixture (GM) model was developed to identify trucks and to estimate truck exposure from ILD data. Using the identified vehicle types from the GM model, vehicle interaction metrics were categorized into three groups based on the combination of leading and following vehicle types. The effects of the proposed traffic measures on crash risk were modeled in two different cases of prior- and non-crash using a case-control approach utilizing a conditional logistic regression. Results showed that the vehicle interactions between the leading and following vehicle types were highly associated with crash risk, and further showed different impacts on crash risk by traffic conditions. Specifically, crashes were more likely to occur when a truck following a non-truck had shorter average headway but greater headway variance in heavy traffic while a non-truck following a truck had greater headway variance in light traffic. This study obtained meaningful conclusions that vehicle interactions involved with trucks were significantly related to the crash likelihood rather than the measures that estimate average traffic condition such as total volume or average headway of the traffic stream.

Feasibility of case-control and test-negative designs to evaluate dengue vaccine effectiveness in Malaysia

BACKGROUND

The world's first dengue vaccine [Dengvaxia; Sanofi Pasteur] was licensed in 2015 and others are in development. Real-world evaluations of dengue vaccines will therefore soon be needed. We assessed feasibility of case control (CC) and test-negative (TN) design studies for dengue vaccine effectiveness by measuring associations between socio-demographic risk factors, and hospitalized dengue outcomes, in Malaysia.

METHODS

Following ethical approval, we conducted hospital-based dengue surveillance for one year in three referral hospitals. Suspected cases aged 9-25 years underwent dengue virological confirmation by RT-PCR and/or NS1 Ag ELISA at a central laboratory. Two age- and geography-matched hospitalized non-dengue case-controls were recruited for a traditional CC study. Suspected cases testing negative were test-negative controls. Socio-demographic, risk factor and routine laboratory data were collected. Logistic regression models were used to estimate associations between confirmed dengue and risk factors.

RESULTS

We recruited 327 subjects; 155 were suspected of dengue. The planned sample size was not met. 124 (80%) of suspected cases were dengue-confirmed; seven were assessed as severe. Three had missing RT-PCR results; the study recruited 28 test-negative controls. Only 172 matched controls could be recruited; 90 cases were matched with ≥1 controls. Characteristics of cases and controls were mostly similar. By CC design, two variables were significant risk factors for hospitalized dengue: recent household dengue contact (OR: 54, 95% CI: 7.3-397) and recent neighbourhood insecticidal fogging (OR: 2.1; 95% CI: 1.3-3.6). In the TN design, no risk factors were identified. In comparison with gold-standard diagnostics, routine tests performed poorly.

CONCLUSIONS

The CC design may be more appropriate than the TN design for hospitalized dengue vaccine effectiveness studies. Selection bias in case control selection could be minimized by protocol changes more easily than increasing TN design control numbers, because early-stage dengue diagnosis in endemic countries is highly specific. MREC study approval: (39)KKM/NIHSEC/P16-1334.

CTC phenotyping for a preoperative assessment of tumor metastasis and overall survival of pancreatic ductal adenocarcinoma patients

BACKGROUND

The evaluation for surgical resectability of pancreatic ductal adenocarcinoma (PDAC) patients is not only imaging-based but highly subjective. An objective method is urgently needed. We report on the clinical value of a phenotypic circulating tumor cell (CTC)-based blood test for a preoperative prognostic assessment of tumor metastasis and overall survival (OS) of PDAC patients.

METHODS

Venous blood samples from 46 pathologically confirmed PDAC patients were collected prospectively before surgery and immunoassayed using a specially designed TU-chip™. Captured CTCs were differentiated into epithelial (E), mesenchymal and hybrid (H) phenotypes. A further 45 non-neoplastic healthy donors provided blood for cell line validation study and CTC false positive quantification.

FINDINGS

A validated multivariable model consisting of disjunctively combined CTC phenotypes: "H-CTC≥15.0 CTCs/2ml OR E-CTC≥11.0 CTCs/2ml" generated an optimal prediction of metastasis with a sensitivity of 1.000 (95% CI 0.889-1.000) and specificity of 0.886 (95% CI 0.765-0.972). The adjusted Kaplan-Meier median OS constructed using Cox proportional-hazard models and stratified for E-CTC < 11.0 CTCs/2 ml was 16.5 months and for E-CTC ≥ 11.0 CTCs/2 ml was 5.5 months (HR = 0.050, 95% CI 0.004-0.578, P = .016). These OS results were consistent with the outcome of the metastatic analysis.

INTERPRETATION

Our work suggested that H-CTC is a better predictor of metastasis and E-CTC is a significant independent predictor of OS. The CTC phenotyping model has the potential to be developed into a reliable and accurate blood test for metastatic and OS assessments of PDAC patients. FUND: National Natural Science Foundation of China; Zhejiang Province Science and Technology Program; China Scholarship Council.

Abnormal Cortical and Trabecular Bone in Youth With Type 1 Diabetes and Celiac Disease

OBJECTIVE

This study compared bone health in youth with type 1 diabetes and celiac disease (CD) versus type 1 diabetes alone.

RESEARCH DESIGN AND METHODS

This was a case-control study of 42 youth with coexisting type 1 diabetes and CD and 40 with type 1 diabetes matched for age, sex, diabetes duration, and HbA_1c. Bone mineral density (BMD), bone mineral content (BMC), and BMC-to-lean tissue mass (LTM) ratio were measured using DXA and reported as z-scores for height. Total, trabecular, and cortical bone and muscle parameters were measured using peripheral quantitative computed tomography (pQCT) and reported as z-scores for age.

RESULTS

Mean age at assessment was 14.3 ± 3.1 years; diabetes duration, 8.0 ± 3.5 years; HbA_1c, 8.2 ± 1.5% (66 ± 5 mmol/mol); and 25-hydroxy vitamin D, 71 ± 21 nmol/L. Comparing youth with coexisting CD versus type 1 diabetes alone, DXA showed lower BMC-to-LTM ratio (0.37 ± 1.12 vs. 0.73 ± 2.23, P = 0.007) but no difference in total BMD. Youth with coexisting CD also had lower BMC-to-LTM ratio versus the general population (P = 0.04). Radial pQCT showed lower total BMC (-0.92 ± 1.40 vs. -0.26 ± 1.23, P = 0.03) despite similar bone and muscle cross-sectional area. In multivariable linear regression, lower BMC was associated with higher insulin dose (P = 0.03) but not HbA_1c.

CONCLUSIONS

Youth with both type 1 diabetes and CD have lower BMC relative to LTM and lower BMC, indicating abnormal trabecular and cortical bone development despite similar bone and muscle size. These findings suggest that the two conditions confer a lower bone turnover state. We recommend further examination of bone health in this population; future research should examine early interventions to improve bone health.

Acculturation stress and allostatic load among Mexican immigrant women

OBJECTIVES

this case-control study compared levels of stress and allostatic load (AL) among Mexican women in the US ( n =19) and Mexico ( n = 40).

METHOD

measures of stress included the Perceived Stress Scale (PSS) and the Hispanic Women's Social Stressor Scale (HWSSS). A composite measure of 8 indicators of AL (systolic and diastolic blood pressure, body mass index (BMI), waist-to-hip ratio, total cholesterol, glycated hemoglobin (hemoglobin A1C), triglycerides and C-reactive protein) was calculated.

RESULTS

there were no significant group differences in AL between Mexican and Mexican immigrant women ( t = 1.55, p = .126). A principal component factor analysis was conducted on the 8 AL indicators; a 2-factor solution explained 57% of the variance. Group differences in the two AL factors were analyzed using MANOVA. BMI and waist-to-hip ratios were lower, but blood pressure and triglycerides were higher in the US group and were mediated by time in the US. Greater acculturation stress was significantly related to increased waist-to-hip ratio ( r = .57, p = .02).

FINAL REMARKS

findings suggest some measures of AL increased with time in the US, and acculturation stress may be a significant factor.