Compared to what? Finding controls for case-control studies

Identification of Potential Plasma Biomarkers for Abdominal Aortic Aneurysm Using Tandem Mass Tag Quantitative Proteomics

Plasma biomarkers that identify abdominal aortic aneurysm (AAA) rupture risk would greatly assist in stratifying patients with small aneurysms. Identification of such biomarkers has hitherto been unsuccessful over a range of studies using different methods. The present study used an alternative proteomic approach to find new, potential plasma AAA biomarker candidates. Pre-fractionated plasma samples from twelve patients with AAA and eight matched controls without aneurysm were analyzed by mass spectrometry applying a tandem mass tag (TMT) technique. Eight proteins were differentially regulated in patients compared to controls, including decreased levels of the enzyme bleomycin hydrolase. The down-regulation of this enzyme was confirmed in an extended validation study using an enzyme-linked immunosorbent assay (ELISA). The TMT-based proteomic approach thus identified novel potential plasma biomarkers for AAA.

Intestinal Barrier Dysfunction and Microbial Translocation in Human Immunodeficiency Virus-Infected Pregnant Women Are Associated With Preterm Birth

Background

Preterm birth (PTB) rates are high in human immunodeficiency virus (HIV)-infected populations, even when on treatment. Still, only a subset of all births in HIV-infected pregnant women result in PTB, suggesting that risk factors other than HIV infection itself are also important. Inflammation is a known risk factor in uninfected populations, but its role in HIV-infected population have not been studied; in addition, the immune pathways involved are not clear and noninvasive immune markers with predictive value are lacking. Our objective was to determine the association of select markers of inflammation with PTB in HIV-1-infected pregnant women.

Methods

Within a randomized trial of pregnant women receiving nevirapine (Six-Week Extended-Dose Nevirapine [SWEN] trial), we nested a case-control study (n = 107; 26 cases, 81 controls) to determine the association of maternal inflammation with PTB. Cases were defined as PTB (<37 weeks' gestational age). We assessed inflammation by measuring plasma levels of markers of general inflammation (C-reactive protein [CRP]), intestinal barrier dysfunction (intestinal fatty acid binding protein [I-FABP]), and microbial translocation/monocyte activation (soluble CD14 [sCD14] and CD163 [sCD163]). Multivariable logistic regression was used to determine the odds of PTB per log2 increase of each marker.

Results

In multivariable models, there was increased odds of PTB per unit increase of log2 sCD14 (adjusted odds ratio [aOR], 2.45; 95% confidence interval [CI], 1.24-4.86), log2 sCD163 (aOR, 3.87; 95% CI, 1.43-10.49), and log2 I-FABP (aOR, 2.28; 95% CI, 1.18-4.41) but not log2 CRP (aOR, 0.72; 95% CI, .48-1.09).

Conclusions

Our results show that select immune markers can identify women at higher risk for PTB in HIV-1-infected populations and suggest that modulating gut barrier integrity and microbial translocation may affect PTB.

Clinical Trials Registration

NCT00061321.

Outcomes of Arthroscopic Rotator Cuff Repair in Patients Who Are 70 Years of Age or Older Versus Under 70 Years of Age: A Sex- and Tear Size-Matched Case-Control Study

PURPOSE

To compare the structural and clinical outcomes after arthroscopic rotator cuff repair (ARCR) of a case group aged 70 and above with those of a control group younger than 70, with the 2 groups matched for sex and tear size.

METHODS

The case group, comprising 53 patients 70 or older, and the control group, comprising 159 patients younger than 70, all received ARCR to 1 shoulder with symptomatic full-thickness rotator cuff tear. The case and the control subjects, who were matched for sex and tear size to minimize bias related to tendon healing, received ARCR during the same period. The mean age was 71.8 ± 2.6 years in the case group and 59.3 ± 7.1 years in the control group. The minimum follow-up period was 1 year in both groups. Cuff integrity was evaluated using ultrasonography. Structural and clinical outcomes of the 2 groups were compared.

RESULTS

Regarding structural outcomes, the complete healing, partial-thickness retear, and full-thickness retear rates were 66% (35/53), 15% (8/53), and 19% (10/53) in the case group, and 68% (108/159), 19% (30/159), and 13% (21/159), respectively, in the control group. The 2 groups had no significantly different retear rates (P = .52). Regarding clinical outcomes, the mean improvements in range of motion, pain, muscle strength, and age- and sex-matched Constant scores were not significantly different between the 2 groups (P > .37). The preoperative tear size was significantly associated with retear in both studied groups (P = .02).

CONCLUSIONS

The clinical and structural outcomes of ARCR in patients 70 or older with symptomatic full-thickness rotator cuff tear are comparable with those in patients younger than 70 with at least 1-year follow-up. Preoperative tear size, a biological factor, is a strong predictor for retear.

LEVEL OF EVIDENCE

Level III, a retrospective comparative (case-control) study.

Current but not past hepatitis B virus infection is associated with a decreased risk of nonalcoholic fatty liver disease in the Chinese population: A case-control study with propensity score analysis

The relation between hepatitis B virus (HBV) infection and fatty liver has been addressed by several observational studies, but their results remain controversial. To date, no study has precisely investigated the association of current and past HBV infection with the risk of nonalcoholic fatty liver disease (NAFLD) in the Chinese population. Therefore, we conducted a hospital-based case-control study in southwestern China to clarify this issue. A total of 631 newly ultrasound-diagnosed NAFLD cases and 2357 controls were selected from 123 243 consecutive patients admitted to a tertiary-care hospital between January 2015 and December 2016. Multivariate logistic regression was employed to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). A propensity score was developed for adjustment and matching. Subgroup analysis was conducted to identify potential effect modifiers. Current and past HBV infection had an overall prevalence of 9.7% and 55.2%, respectively. In the fully adjusted model, current HBV infection was associated with a decreased risk of NAFLD (OR 0.64; 95% CI 0.42-0.95). A similar inverse association was observed in both propensity-score-adjusted (OR 0.58; 95% CI 0.40-0.86) and propensity-score-matched analyses (OR 0.61; 95% CI 0.40-0.92).The inverse association was stronger in patients with hypertension than in those without (P_interaction  = .018).No significant association between past HBV infection and NAFLD risk was found. In conclusion, current but not past HBV infection is associated with a decreased risk of NAFLD in the Chinese population. The corresponding biological mechanisms remain to be elucidated.

Risk factors associated with nonsteroidal anti-inflammatory drugs (NSAIDs)-induced gastrointestinal bleeding resulting on people over 60 years old in Beijing

Gastrointestinal (GI) bleeding is an unwanted side effect common to all chemical types of nonsteroidal anti-inflammatory drugs (NSAIDs), particularly in elderly people. However, the risk factors of GI bleeding associated with NSAIDs for elderly people remain unknown. This study aims to evaluate the risks of GI bleeding associated with NSAIDs in 4728 elderly people over 60 years old based on database from a hospital in Beijing.This retrospective hospital-based study included 4728 patients over 60 years old prescribed with NSAIDs, of which 928 patients had GI bleeding and 3800 did not have. Odds ratios (OR) for the risk of GI bleeding associated with NSAIDs were determined by logistic regression analysis. Mean Decrease Gini (MDG) involved in random forest algorithm was used to rank the associated factors with GI bleeding.In multivariate analysis, family history of GI bleeding (OR, 3.348; P = .000), history of peptic ulcers (OR, 4.068; P = .000), history of cardiovascular and cerebrovascular disease (OR, 1.476; P = .001), diabetes mellitus (OR, 1.408; P = .000), antiplatelet drugs (OR, 3.106; P = .000), Helicobacter pylori infection (OR, 1.312; P = .001), cholesterol level (OR, 0.516; P = .000), upper abdominal discomfort (OR, 3.467; P = .000), anorexia (OR, 2.038; P = .000), and NSAIDs used for 0.5 to 3 months (OR, 0.780; P = .000) were associated with GI bleeding. After ranked the MDG of each factor, the top 5 ranked factors associated with GI bleeding were melena, hematemesis, antiplatelet drugs, cholesterol level, and upper abdominal discomfort.We found that family history of GI bleeding, history of peptic ulcers, history of cardiovascular and cerebrovascular disease, diabetes mellitus, antiplatelet drugs, Helicobacter pylori infection, hypocholesterolemia, and NSAIDs used for 0.5 to 3 months were independent risk factors for GI bleeding on people over 60 years old. Meanwhile, upper abdominal discomfort might be the predictor of GI bleeding associated with NSAIDs elderly users.

Confined placental mosaicism revisited: Impact on pregnancy characteristics and outcome

OBJECTIVES

We wanted to re-evaluate the influence of confined placental mosaicism subtypes (type 2 and type 3) on pregnancy characteristics and outcome.

MATERIAL AND METHODS

From July 2009 to December 2015, 5512 chorionic villus samplings were performed in our Fetal Medicine Center. Conventional karyotyping was performed after long-term and short-term cultured villi to define type 2 or type 3 confined placental mosaicisms. Karyotype after amniocentesis was performed to exclude true fetal mosaicism, when appropriate. Pregnancy characteristics and outcomes were collected and compared to a control population.

RESULTS

Thirty-six (0.65%) confined placental mosaicisms were observed (13 type 2 and 23 type 3). Nuchal translucency was not increased for type 2 and type 3 confined placental mosaicisms. Pregnancy characteristics and outcomes were comparable between type 2 confined placental mosaicisms and the control population. In type 3 confined placental mosaicisms, median first trimester serum pregnancy-associated plasma protein A was lower than for the control population (p<0.001), preterm births were noticed in 56% (p<0.001), small for gestational age newborns in 74% (p<0.001), and adverse pregnancy outcome was reported in 35% (p<0.01).

CONCLUSION

Although type 2 confined placental mosaicisms appeared to have no influence on pregnancy characteristics and outcome, type 3 confined placental mosaicisms were associated with low levels of first trimester serum pregnancy-associated plasma protein A, preterm birth, small for gestational age newborns, and adverse pregnancy outcomes.

Symptoms Associated With Attention Deficit/Hyperactivity Disorder and Autism Spectrum Disorders in School-Aged Children Prenatally Exposed to Substances

Prenatal exposure to substances may influence a child's neurodevelopment and impact on subsequent mental health. In a hospital-based population of school-aged children prenatally exposed to opiates and a number of illicit substances (n = 57), we evaluated mental health symptoms associated with attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASD) using the Swanson, Nolan, and Pelham Questionnaire, revision IV (SNAP-IV) and the Autism Spectrum Screening Questionnaire (ASSQ) and compared the scores to a reference group which comprised children from the population-based Bergen Child Study (n = 171). Prenatally exposed children had significantly higher SNAP-IV scores associated with ADHD symptoms in both areas of inattention and hyperactivity/impulsivity and also reported a higher ASSQ score related to an increased number of symptoms associated with ASD, compared with the reference group. Of tested predictors of mental health outcomes in the exposed group, the intelligence quotient was a strong predictor of most mental health outcomes, and neonatal abstinence syndrome was a predictor of inattention. In conclusion, prenatally exposed children had more mental health symptoms associated with ADHD and ASD, compared with the reference group.

How the personalities of medical students at the National University of Singapore differ from those of the local non-medical undergraduate population: a cross-sectional study

INTRODUCTION

Integrity and willingness to contribute to society are desired traits of medical students beyond academic excellence. We investigated the personality traits of medical students at the National University of Singapore (NUS), who were about to become doctors. Personality traits were compared with a peer population of local university students.

METHODS

This study was conducted between October 2013 and December 2014. Year 4 medical students were administered the Revised NEO (Neuroticism-Extraversion-Openness) Personality Inventory (NEO PI-R), a 240-item Likert scale personality test. Test data was analysed by an institutional psychologist and compared to a separate sample of 377 non-medical students who were peers at the same university taking psychology as a module. Data was collated and analysed.

RESULTS

65 Year 4 medical students completed the NEO PI-R personality test. The personalities of Year 4 medical students at NUS differed from their peers in all domains except for openness. NUS medical students generally had less neuroticism, and were more extroverted, agreeable and conscientious than their peers.

CONCLUSION

Personality testing of NUS Year 4 medical students showed many of the desired traits of a doctor when compared to their peers at the same university.

Diet and Melanoma Risk: Effects of Choice of Hospital versus Population Controls

Aims and background

Hospital-referred subjects are widely used as controls in studies on the relation between diet and cancer risk. However, concern has been raised about the potential for bias of such type of referents, and few studies seem to have examined their reliability in estimating dietary habits of the underlying general population.

Methods

In a northern Italian setting, the differences in dietary patterns between 41 individuals referred for non-neoplastic lesions to hospital surgical outpatient units and age- and sex-matched subjects drawn from the general population were examined. The effects of such differences when carrying out a case-control study on a neoplastic disease, cutaneous melanoma, were also analyzed. Dietary intake was assessed using the EPIC food frequency questionnaire.

Results

Population controls showed higher intakes of energy, animal proteins and animal fats compared with sex- and age-matched hospital controls, whereas intake of carbohydrates and fiber was comparable. An excess melanoma risk associated with intake of animal proteins and fats emerged when hospital controls were used as the referent group, whereas no such relation was detected when cases were compared to population controls.

Conclusions

The results suggest that hospital-referred subjects may not reflect dietary habits of the underlying general population and may be unsuitable for case-control studies concerning the relation between diet and cancer risk.

Longitudinal pharmacoepidemiological and health services research for substance users in treatment: protocol of the Belgian TDI-IMA linkage

Background

Not much is known about the health seeking behavior of people with substance use disorders before they enter specialized treatment and afterwards. This paper explains in detail the protocol that has been followed to establish the Belgian TDI-IMA-database, which is linking two separate databases: the Treatment Demand Indicator (TDI) and the database of the Intermutualistic Agency (IMA). The Treatment Demand Indicator is measuring incidence of people with substance use disorders entering drug treatment. The IMA-database covers data, collected in the framework of the compulsory Belgian health care and benefits insurance program, on reimbursed medication and the use of reimbursed health services. The linkage results in pharmacoepidemiological and health service data for people who were in treatment for substance use disorders and for a group of comparators.

Methods

The TDI-database was linked to the IMA-database for the period between 01/01/2008 and 31/12/2017, based on the national identification number of patients who have been in alcohol or drug treatment between 01/01/2011 and 31/12/2014. Through this linkage, pharmacoepidemiological and health service data became available for at least 3 years before the first registered episode in the TDI-database till at least 3 years after the first episode. For each person in TDI four comparators, who were not in specialized treatment, were matched on age, sex and place of residence.

Discussion

The TDI-IMA-database allows for an analysis of health seeking behavior and health care pathways of people before and after they entered specialized alcohol and drug treatment. The presented protocol could be used in other European countries to establish a linkage between existing health databases. This will allow for a better understanding of the health care needs of patients with substance use disorders.

Multicenter evaluation of signalment and comorbid conditions associated with aortic thrombotic disease in dogs

OBJECTIVE To assess signalment and concurrent disease processes in dogs with aortic thrombotic disease (ATD). DESIGN Retrospective case-control study. ANIMALS Dogs examined at North American veterinary teaching hospitals from 1985 through 2011 with medical records submitted to the Veterinary Medical Database. PROCEDURES Medical records were reviewed to identify dogs with a diagnosis of ATD (case dogs). Five control dogs without a diagnosis of ATD were then identified for every case dog. Data were collected regarding dog age, sex, breed, body weight, and concurrent disease processes. RESULTS ATD was diagnosed in 291 of the 984,973 (0.03%) dogs included in the database. The odds of a dog having ATD did not differ significantly by sex, age, or body weight. Compared with mixed-breed dogs, Shetland Sheepdogs had a significantly higher odds of ATD (OR, 2.59). Protein-losing nephropathy (64/291 [22%]) was the most commonly recorded concurrent disease in dogs with ATD. CONCLUSIONS AND CLINICAL RELEVANCE Dogs with ATD did not differ significantly from dogs without ATD in most signalment variables. Contrary to previous reports, cardiac disease was not a common concurrent diagnosis in dogs with ATD.

Forced sexual intercourse and its association with HIV status among people attending HIV Voluntary Counseling and Testing in a healthcare center in Kinshasa (DRC)

INTRODUCTION

Sexual violence, an HIV determinant, is an integrated behavior in the D.R.Congo. We aimed to analyze the prevalence of forced sexual intercourse (FSI) among people receiving HIV Voluntary Counseling and Testing in a hospital in Kinshasa, and its association with socio-demographics, behaviors and HIV status.

METHODOLOGY

Case-control study (2010-2012). Two-hundred and seventy-four cases with a new HIV+ test and 1,340 controls with an HIV- test were interviewed about HIV-related knowledge, attitudes and behaviors, including FSI.

RESULTS

Thirty-four percent of the participants declared having had FSI (38% of women and 32% of men). Being a woman, aged 25-49 and reporting multiple sexual partners were associated with reporting FSI. For men, being single was protective against FSI; and cohabiting, having a high socioeconomic status, and alcohol consumption increased the odds. For women, being single, divorced/separated and widow was associated with reporting FSI. A significant positive association was found between FSI and an HIV positive test.

CONCLUSION

Among our Congolese population, FSI was strongly associated with HIV infection and it was also associated with alcohol consumption and multiple sexual partnerships, other key HIV determinants. These behaviors need to be identified as potential risk factors of FSI during counseling interventions. Researchers, practitioners and decision-makers should work together to get violence prevention integrated into health, social and educational policies.

Long-term survival of beta thalassemia major patients treated with hematopoietic stem cell transplantation compared with survival with conventional treatment

Allogeneic hematopoietic stem cell transplantation (HSCT) in thalassemia remains a challenge. We reported a single-centre case-control study of a large cohort of 516 children and adult patients treated with HSCT or blood transfusion support and iron chelation therapy; 258 patients (median age 12, range 1-45) underwent sibling (67%) or unrelated (33%) HSCT; 97 patients were adults (age ≥ 16 years). The median follow-up after HSCT was 11 years (range 1-30). The conditioning regimen was busulfan (80.6%) or treosulfan-based (19.4%). A cohort of 258 age-sex matched conventionally treated (CT) patients was randomly selected. In transplanted patients the 30-year overall survival (OS) and thalassemia-free survival (TFS) were 82.6 ± 2.7% and 77.8 ± 2.9%, compared to the OS of 85.3 ± 2.7% in CT patients (P = NS); The incidence of grade II-IV acute and chronic graft versus host disease (GvHD) was 23.6% and 12.9% respectively. The probability of rejection was 6.9%. Transplant-related mortality (TRM) (13.8%) was similar to the probability of dying of cardiovascular events in CT patients (12.2%). High-risk Pesaro score (class 3) was associated with lower OS (OR = 1.99, 95% C.I.=1.31-3.03) and TFS (OR = 1.54, 95% C.I.=1.12-2.12). In adult patients, the 23-years OS and TFS after HSCT were 70 ± 5% and 67.3 ± 5%, compared to 71.2 ± 5% of OS in CT (P = NS). Finally, treosulfan was associated with lower risk of acute GvHD (P = .004; OR = 0.28, 95% C.I.=0.12-0.67). In conclusion, the 30-year survival rate of ex-thalassemia patients after HSCT was similar to that expected in CT thalassemia patients, with the vast majority of HSCT survivors cured from thalassemia.

Schistosoma, other helminth infections, and associated risk factors in preschool-aged children in urban Tanzania

Background

Despite the high prevalence of helminth infections among preschool-aged children, control programs in sub-Saharan countries primarily focus on school-aged populations. We assessed the prevalence of helminth infections and determined risk factors for infection among preschool-aged children in the urban setting of Dar es Salaam, Tanzania.

Methodology

Starting in October 2015, we conducted a 12-month prospective study among tuberculosis (TB)-exposed children under the age of 5 years and unexposed controls from neighboring households. At the time of recruitment, we collected medical histories, assessed development and cognitive functions, and performed medical examinations. We performed full blood cell counts and screened for HIV and malaria. Point-of-care circulating cathodic antigen (POC-CCA), urine filtration, Kato-Katz, FLOTAC, and Baermann tests were employed to detect helminth infections in urine and stool. Helminth infections were stratified for Schistosoma and other helminths to identify risk factors, using logistic regression.

Principal findings

We included 310 children with a median age of 26 months (inter quartile range 17–42 months) in the study. Among these, 189 were TB-exposed and 121 TB-unexposed. Two thirds of the children were anemic (hemoglobin level <11 g/dl) and the HIV prevalence was 1.3%. Schistosoma spp. was the predominant helminth species (15.8%; 95% confidence interval [CI] 12.1–20.3%). Other helminth infections were less frequent (9.0%, 95% CI 6.3–12.8%). Poor hygiene, use of household water sources, and TB-exposure were not associated with helminth infection. Development and cognitive scores did not significantly differ in helminth-infected and uninfected peers, but hemoglobin levels were significantly lower in helminth-infected children (10.1 g/dl vs. 10.4 g/dl, p = 0.027).

Conclusions/significance

In Dar es Salaam, a city with more than 4 million inhabitants, the prevalence of Schistosoma spp. infection among preschool-aged children was unexpectedly high. Setting-specific interventions that target preschool-aged children and urban settlements should be considered to reduce the transmission of Schistosoma and other helminth infections and to improve children’s health.

In many African countries, children under the age of 5 years are at considerable risk of acquiring parasitic worm infections. Yet, most of the neglected tropical disease control programs in Africa do not include preschool-aged children in deworming campaigns. Chronic parasitic worm infections may impair children’s growth and their cognitive development. We conducted a 12-month prospective study of children younger than 5 years in the Temeke district, Dar es Salaam—the economic capital of Tanzania—to assess the prevalence of parasitic worm infections. Among 310 included children, we found that one in six children was infected with the blood fluke Schistosoma, while one in 11 children were infected with soil-transmitted helminths. Anemia was found among 65% of children, particularly among those infected with parasitic worms. The high prevalence of Schistosoma infection in this urban setting, despite improved water supply and sanitation as well as limited open freshwater contact shows the pressing need to identify parasitic worm transmission hotspots in urban areas. Setting-specific interventions targeting preschool-aged children and urban settlements, among others, should be considered to reduce the transmission of Schistosoma and other parasitic worm infections.

Clinical Application of Targeted Deep Sequencing in Solid-Cancer Patients and Utility for Biomarker-Selected Clinical Trials

Molecular profiling of actionable mutations in refractory cancer patients has the potential to enable "precision medicine," wherein individualized therapies are guided based on genomic profiling. The molecular-screening program was intended to route participants to different candidate drugs in trials based on clinical-sequencing reports. In this screening program, we used a custom target-enrichment panel consisting of cancer-related genes to interrogate single-nucleotide variants, insertions and deletions, copy number variants, and a subset of gene fusions. From August 2014 through April 2015, 654 patients consented to participate in the program at Samsung Medical Center. Of these patients, 588 passed the quality control process for the 381-gene cancer-panel test, and 418 patients were included in the final analysis as being eligible for any anticancer treatment (127 gastric cancer, 122 colorectal cancer, 62 pancreatic/biliary tract cancer, 67 sarcoma/other cancer, and 40 genitourinary cancer patients). Of the 418 patients, 55 (12%) harbored a biomarker that guided them to a biomarker-selected clinical trial, and 184 (44%) patients harbored at least one genomic alteration that was potentially targetable. This study demonstrated that the panel-based sequencing program resulted in an increased rate of trial enrollment of metastatic cancer patients into biomarker-selected clinical trials. Given the expanding list of biomarker-selected trials, the guidance percentage to matched trials is anticipated to increase.

IMPLICATIONS FOR PRACTICE

This study demonstrated that the panel-based sequencing program resulted in an increased rate of trial enrollment of metastatic cancer patients into biomarker-selected clinical trials. Given the expanding list of biomarker-selected trials, the guidance percentage to matched trials is anticipated to increase.

Stressful and Traumatic Experiences among Women with Alcohol Use Disorders in India

AIM

The aim of the present study was to examine lifetime stressful and traumatic experiences among women with alcohol use disorders (AUDs).

METHODS

The sample comprised of two groups: a clinical group of 35 women with a diagnosis of AUD and a comparison group of 60 women drawn from the community. After screening out, the participants were administered Life Stressor Checklist-Revised.

RESULTS

On an average, clinical group was exposed to 7.57 (standard deviation [SD] = 4.14) stressful events and comparison group was exposed to 4.03 (SD = 2.80) stressful events across the lifespan (t = 4.976; P < 0.001). Clinical group reported a high number of childhood abuse and interpersonal traumas across lifespan than comparison group. The relationship between adverse life experiences and alcohol abuse among women was bidirectional.

CONCLUSION

Understanding the nature and experiences of trauma in this group has implications for planning gender-sensitive treatment programs for women seeking help for AUDs in India.

Sensitivity of self-reported opioid use in case-control studies: Healthy individuals versus hospitalized patients

Background

Several case-control studies have shown associations between the risk of different cancers and self-reported opium use. Inquiring into relatively sensitive issues, such as the history of drug use, is usually prone to information bias. However, in order to justify the findings of these types of studies, we have to quantify the level of such a negative bias. In current study, we aimed to evaluate sensitivity of self-reported opioid use and suggest suitable types of control groups for case-control studies on opioid use and the risk of cancer.

Methods

In order to compare the validity of the self-reported opioid use, we cross-validated the response of two groups of subjects 1) 178 hospitalized patients and 2) 186 healthy individuals with the results of their tests using urine rapid drug screen (URDS) and thin layer chromatography (TLC). The questioners were asked by trained interviewers to maximize the validity of responses; healthy individuals were selected from the companions of patients in hospitals.

Results

Self-reported regular opioid use was 36.5% in hospitalized patients 19.3% in healthy individuals (p-value> 0.001).The reported frequencies of opioid use in the past 72 hours were 21.4% and 11.8% in hospitalized patients and healthy individuals respectively. Comparing their responses with the results of urine tests showed a sensitivity of 77% and 69% among hospitalized patients and healthy individuals for self-reports (p-value = 0.4). Having corrected based on the mentioned sensitivities; the frequency of opioid regular use was 47% and 28% in hospitalized patients and healthy individuals, respectively. Regular opioid use among hospitalized patients was significantly higher than in healthy individuals (p-value> 0.001).

Conclusion

Our findings showed that the level of opioid use under-reporting in hospitalized patients and healthy individuals was considerable but comparable. In addition, the frequency of regular opioid use among hospitalized patients was significantly higher than that in the general population. Altogether, it seems that, without corrections for these differences and biases, the results of many studies including case-control studies on opioid use might distort findings substantially.

Epidemiological Methods

This chapter provides an overview of the most common epidemiological designs used in clinical studies to better understand innate anti-viral immunity. Studies to assess risk factors as well as interventions are described.

Perinatal Risk and Protective Factors for Pediatric Abusive Head Trauma: A Multicenter Case-Control Study

OBJECTIVE

To estimate associations between factors recorded in pregnancy and the first week of life and subsequent abusive head trauma.

STUDY DESIGN

Multicenter, retrospective case-control study of perinatal records from 142 cases of abusive head trauma and 550 controls, matched by date and hospital of birth from 1991 to 2010. Multiple logistic regression assessed the relationship between perinatal exposures and abusive head trauma.

RESULTS

The risk of abusive head trauma decreased with increasing maternal age (OR, 0.91 per year; 95% CI 0.85-0.97) and increasing gestational age at birth (OR 0.79 per week; 95% CI 0.69-0.91). Mothers of cases were more likely to be Māori (OR 4.61; 95% CI 1.98-10.78), to be single (OR 5.10; 95% CI 1.83-14.23), have recorded social concerns (OR 4.29; 95% CI 1.32-13.91), and have missing data for antenatal care, partner status, social concerns, and substance abuse (OR 13.53; 95% CI 2.39-76.47). Case mothers were more likely not to take supplements in pregnancy (OR 3.53; 95% CI 1.30-9.54), to have membrane rupture longer than 48 hours before delivery (OR 13.01; 95% CI 2.84-59.68), and to formula feed (OR for mixed breast and formula feeding 6.06; 95% CI 2.39-15.36) before postnatal discharge (median 3 days).

CONCLUSIONS

Factors associated with subsequent abusive head trauma can be identified from routine perinatal records. Targeted interventions initiated perinatally could possibly prevent some cases of abusive head trauma. However, any plans for targeted prevention strategies should consider not only those with identified risk factors but also those for which data are missing.

Mental Health in School-Aged Children Prenatally Exposed to Alcohol and Other Substances

Prenatal exposure to substances can possibly influence a child's neurodevelopment and may impact on subsequent mental health. We investigated the mental health status of school-aged children referred to a pediatric hospital with a history of prenatal exposure to alcohol or other substances. Mental health was assessed using the Strengths and Difficulties Questionnaire and compared with a reference group. A total of 105 of 128 (82%) eligible children prenatally exposed to substances participated in the study, with 48 children exposed to alcohol and 57 to other substances. Strengths and Difficulties Questionnaire subscale mean scores, total difficulties scores, and total impact scores were statistically significantly higher in the group of exposed children, compared with the reference group. In this hospital-based population of school-aged children prenatally exposed to alcohol or other substances, the exposed group had an increased risk of mental health problems, compared with the reference group.

Organizational, Regional, and Community Factors Determining Protocol Compliance for Patients With Acute Myocardial Infarction

This study examined factors determining hospital compliance to Hospital Quality Alliance's protocol for patients with myocardial infarction. Using a spatially matched sample of 132 Magnet and 264 non-Magnet hospitals, multivariate regressions determined significant hospital characteristics associated with compliance per Hospital Quality Alliance protocol. Adherence to the Hospital Quality Alliance protocols varied widely by hospital characteristics. Registered nurse staffing/bed was a key factor determining patient care quality variation. Quality of care practices such as protocol compliance should be measured and examined separately.

Site-specific familial risk and survival of familial and sporadic head and neck cancer

The vast majority of head and neck cancers (HNCs) are sporadic squamous cell carcinomas, smoking and heavy drinking being the main risk factors. However, little is known about the possible role of family history and the importance of inherited factors versus shared environment. We used Swedish population-based registries to study the family history of HNC. In order to estimate the risk for family members to get the same cancer, and the risk for cancer-specific death in patients with a family history of HNC compared with patients without a family history, multivariate Cox proportional hazards analyses were performed. A 1.43-fold increased risk for developing HNC in the first-degree relatives (FDRs) of HNC patients [hazard ratio (HR), 1.43; 95% CI, 1.28-1.61] was found, when compared with relatives of healthy controls. In spouses of patients with HNC, the risk for developing any HNC was moderately increased (HR, 1.25; 95% CI, 1.01-1.53), compared with spouses of healthy controls. In addition, a 1.34-fold increased risk for death of HNC was found in HNC patients with a family history of HNC (HR, 1.34; 95% CI, (1.03-1.73) compared with HNC patients without a family history. We found an increased risk for HNC in relatives and spouses of HNC patients, when compared with family members of healthy controls. This suggests that in addition to inherited factors, shared environmental factors have a significant role in the development of the cancer. Family history of HNC was associated with worse survival in a newly diagnosed HNC patient.

Case-control vaccine effectiveness studies: Data collection, analysis and reporting results

The case-control methodology is frequently used to evaluate vaccine effectiveness post-licensure. The results of such studies provide important insight into the level of protection afforded by vaccines in a 'real world' context, and are commonly used to guide vaccine policy decisions. However, the potential for bias and confounding are important limitations to this method, and the results of a poorly conducted or incorrectly interpreted case-control study can mislead policies. In 2012, a group of experts met to review recent experience with case-control studies evaluating vaccine effectiveness; we summarize the recommendations of that group regarding best practices for data collection, analysis, and presentation of the results of case-control vaccine effectiveness studies. Vaccination status is the primary exposure of interest, but can be challenging to assess accurately and with minimal bias. Investigators should understand factors associated with vaccination as well as the availability of documented vaccination status in the study context; case-control studies may not be a valid method for evaluating vaccine effectiveness in settings where many children lack a documented immunization history. To avoid bias, it is essential to use the same methods and effort gathering vaccination data from cases and controls. Variables that may confound the association between illness and vaccination are also important to capture as completely as possible, and where relevant, adjust for in the analysis according to the analytic plan. In presenting results from case-control vaccine effectiveness studies, investigators should describe enrollment among eligible cases and controls as well as the proportion with no documented vaccine history. Emphasis should be placed on confidence intervals, rather than point estimates, of vaccine effectiveness. Case-control studies are a useful approach for evaluating vaccine effectiveness; however careful attention must be paid to the collection, analysis and presentation of the data in order to best inform evidence-based vaccine policies.

Case-control vaccine effectiveness studies: Preparation, design, and enrollment of cases and controls

Case-control studies are commonly used to evaluate effectiveness of licensed vaccines after deployment in public health programs. Such studies can provide policy-relevant data on vaccine performance under ‘real world’ conditions, contributing to the evidence base to support and sustain introduction of new vaccines. However, case-control studies do not measure the impact of vaccine introduction on disease at a population level, and are subject to bias and confounding, which may lead to inaccurate results that can misinform policy decisions. In 2012, a group of experts met to review recent experience with case-control studies evaluating the effectiveness of several vaccines; here we summarize the recommendations of that group regarding best practices for planning, design and enrollment of cases and controls. Rigorous planning and preparation should focus on understanding the study context including healthcare-seeking and vaccination practices. Case-control vaccine effectiveness studies are best carried out soon after vaccine introduction because high coverage creates strong potential for confounding. Endpoints specific to the vaccine target are preferable to non-specific clinical syndromes since the proportion of non-specific outcomes preventable through vaccination may vary over time and place, leading to potentially confusing results. Controls should be representative of the source population from which cases arise, and are generally recruited from the community or health facilities where cases are enrolled. Matching of controls to cases for potential confounding factors is commonly used, although should be reserved for a limited number of key variables believed to be linked to both vaccination and disease. Case-control vaccine effectiveness studies can provide information useful to guide policy decisions and vaccine development, however rigorous preparation and design is essential.

Cholera returns to southern Vietnam in an outbreak associated with consuming unsafe water through iced tea: A matched case-control study

Background

After more than a decade of steadily declining notifications, the number of reported cholera cases has recently increased in Vietnam. We conducted a matched case-control study to investigate transmission of cholera during an outbreak in Ben Tre, southern Vietnam, and to explore the associated risk factors.

Methodology/Principal findings

Sixty of 71 diarrheal patients confirmed to be infected with cholera by culture and diagnosed between May 9 and August 3, 2010 in Ben Tre were consecutively recruited as case-patients. Case-patients were matched 1:4 to controls by commune, sex, and 5-year age group. Risk factors for cholera were examined by multivariable conditional logistic regression. In addition, environmental samples from villages containing case-patients were taken to identify contamination of food and water sources. The regression indicated that drinking iced tea (adjusted odds ratio (aOR) = 8.40, 95% confidence interval (CI): 1.84–39.25), not always boiling drinking water (aOR = 2.62, 95% CI: 1.03–6.67), having the main source of water for use being close to a toilet (aOR = 4.36, 95% CI: 1.37–13.88), living with people who had acute diarrhea (aOR = 13.72, 95% CI: 2.77–67.97), and little or no education (aOR = 4.89, 95% CI: 1.18–20.19) were significantly associated with increased risk of cholera. In contrast, drinking stored rainwater (aOR = 0.17, 95% CI: 0.04–0.63), eating cooked seafood (aOR = 0.27, 95% CI: 0.10–0.73), and eating steamed vegetables (aOR = 0.22, 95% CI: 0.07–0.70) were protective against cholera. Vibrio cholerae O1 Ogawa carrying ctxA was found in two of twenty-five river water samples and one of six wastewater samples.

Conclusions/Significance

The magnitude of the cholera outbreak in Ben Tre was lower than in other similar settings. This investigation identified several risk factors and underscored the importance of continued responses targeting cholera prevention in southern Vietnam. The association between drinking iced tea and cholera and the spread of V. cholerae O1, altered El Tor strains warrant further research. These findings might be affected by a number of limitations due to the inability to capture asymptomatic or mildly symptomatic infections, the possible underreporting of personal unhygienic behaviors, and the purposive selection of environmental samples.

Cholera is a highly contagious, acute diarrheal illness, which poses a profound health threat in many parts of the less developed world. The majority of cases are reported from Sub-Saharan Africa, South-East Asia, and the Americas (i.e., Haiti) where infections are primarily transmitted through ingestion of contaminated water. Today in the era of widely available rehydration therapies and antibiotics, deaths due to cholera are quite rare. Despite this, early detection of contaminated water sources is crucial for directing early interventions for curbing community-wide transmission. The authors found evidence linking an outbreak of cholera in southern Vietnam to consumption of unsafe water, especially drinking iced tea. This finding suggests the need for a water-monitoring system at ice-making plants. Further research is needed to confirm the biological link between iced tea consumption and cholera infection. Larger studies should also be conducted to understand the clinical consequences of infection with the new cholera agent (V. cholerae O1, altered El Tor strains).

Suggestion of BRCA1 c.5339T>C (p.L1780P) variant confer from 'unknown significance' to 'Likely pathogenic' based on clinical evidence in Korea

PURPOSE

We describe a rationale for the re-classification of the BRCA1 c.5539T>C (L1780P) variant using a clinical evidence.

METHODS

A retrospective review was conducted to identify all patients with breast or ovarian cancer and the L1780P variant between 2002 and 2015 at a single institution.

RESULTS

We identified the BRCA1/2 genetic mutation test results of 1223 breast cancer patients and 174 patients with ovarian cancer. Of the 160 BRCA 1/2 variant unknown significance, 16 (10.0%) patients were identified as having the L1780P variant. Among them, 10 had breast cancer, 4 had ovarian cancer, and 2 had both breast and ovarian cancer. Thirteen (81.3%) patients with this variant had family histories of breast or ovarian cancer. Two (16.7%) also had comorbid ovarian cancer. Two patients with this variant showed that co-segregation of the disease in multiple family members and family histories of breast and ovarian cancer. This variant was found to be either absent or at extremely low frequency in general population databases.

CONCLUSION

The L1780P variant might confer to "Likely pathogenic" according to a clinical evidence and the ACMG standards and guidelines. A nation-wide or global survey and a functional analysis are needed to confirm the pathogenicity of the L1780P variant.

Comparative cardiovascular risks of dipeptidyl peptidase 4 inhibitors with other second- and third-line antidiabetic drugs in patients with type 2 diabetes

AIMS

Dipeptidyl peptidase 4 inhibitors (DPP4is) are suggested as a second- and third-line antidiabetic treatment for type 2 diabetes. Previous studies assessed only the cardiovascular effects of DPP4is as a second-line treatment, included sulphonylurea as the only comparator, and yielded inconclusive results on the risk of heart failure. The present study therefore evaluated the comparative cardiovascular risks of DPP4is with other second- and third-line antidiabetic drugs.

METHODS

Based on a large nationwide diabetic cohort, 113 051 patients with type 2 diabetes newly on metformin-based dual or triple therapy were identified in 2009-2011 and followed until 2013, or death if this occurred sooner. Primary interest targeted hospitalizations for ischaemic stroke, myocardial infarction and heart failure. Secondary outcomes were hypoglycaemia and all-cause mortality. Cox proportional hazards models were performed to assess time-to-event hazard ratio between propensity score-matched antidiabetic treatment groups.

RESULTS

DPP4is as a second-line add-on to metformin had a significantly lower stroke risk [hazard ratio (HR) 0.817 (95% confidence interval 0.687, 0.971)] and all-cause mortality [HR 0.825 (0.687, 0.992)] than those for sulphonylurea. DPP4is as a third-line add-on to metformin and sulphonylurea combined dual therapy had a significantly lower risk for stroke [HR 0.826 (0.740, 0.923)] and all-cause mortality [HR 0.784 (0.701, 0.878)] than those for acarbose, and significantly lower risks for stroke [HR 0.653 (0.542, 0.786)], heart failure [HR 0.721 (0.568, 0.917)] and all-cause mortality [HR 0.689 (0.594, 0.703)] than those for meglitinide.

CONCLUSIONS

DPP4is as a second- or third-line add-on treatment provided cardiovascular benefits and posed no increased risks for heart failure, hypoglycaemia or death.

The Association of Specific Constituents of the Fecal Microbiota with Immune-Mediated Brain Disease in Dogs

Meningoencephalomyelitis of unknown origin (MUO) is a common, naturally-occurring, clinical disease of pet dogs. It is an immune-mediated condition that has many similarities with experimental autoimmune encephalitis (EAE) in rodents and so investigation of its pathogenesis may aid in understanding factors that contribute to development of multiple sclerosis in people. Gut microbiota are known to modulate immune responses that influence susceptibility to immune-mediated brain disease. In this study we aimed to compare abundance of specific constituents of the fecal microbiota, namely Faecalibacterium prausnitzii and Prevotellaceae, between dogs diagnosed with MUO and matched controls. Fecal samples were obtained from 20 dogs diagnosed with MUO and 20 control dogs matched for breed, age and gender. Bacterial abundance was measured using qPCR and 16S rRNA sequencing. We found that Prevotellaceae were significantly less abundant in cases compared with controls (p = 0.003) but there was no difference in abundance of F.prausnitzii. There was no evidence of other differences in gut microbiota between groups. These data, derived from this naturally-occurring canine clinical model, provide strong corroborative evidence that high abundance of Prevotellaceae in the gut is associated with reduced risk for developing immune-mediated brain disease.

Male condom use, multiple sexual partners and HIV: a prospective case-control study in Kinshasa (DRC)

In the Democratic Republic of Congo no previous studies have assessed the factors associated with different patterns of condom use and with multiple sexual partners, and the association between condom use simultaneously taking into account multiple sexual partnerships, and HIV infection. We carried out a prospective case-control study. From December 2010 until June 2012, 1630 participants aged 15-49 getting HIV Voluntary Counseling and Testing in a hospital in Kinshasa were selected. Cases were new HIV diagnosis and controls were HIV-negative participants detected along the study period. We recruited 274 cases and 1340 controls that were interviewed about HIV-related knowledge, attitudes and behaviours. Among cases there was a high prevalence of multiple lifetime and concurrent sexual partnerships (89.8% and 20.4%, respectively) and most cases never used condoms with only 1.5% using them consistently. Condom use and multiple partnerships were associated with male, single and high-educated participants. An association was found between multiple lifetime partners and 'any condom use' (OR = 2.99; 95%CI: 2.14-4.19) but not with consistent use. Both having two or more multiple concurrent sexual partners or not using condoms were variables similarly and highly associated to HIV risk. The association found between having two or more concurrent sexual partners and HIV was slightly higher (OR = 3.58, 95%CI:2.31-5.56) than the association found between never condom use and HIV (OR = 3.38, 95%CI:1.15-9.93). We found a high prevalence of multiple lifetime sexual partners and an extremely high prevalence of inconsistent condom use, both strongly associated with HIV seropositivity. Local programmes would benefit from comprehensive interventions targeting all behavioural and sociocultural determinants.

Identification of the Most Accurate Spectral-domain Optical Coherence Tomography Parameters in Eyes With Early High-Tension and Low-Tension Glaucoma

PURPOSE

The aim of the study was to compare the diagnostic ability of macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (pRNFL) thickness in high-tension glaucoma (HTG) and low-tension glaucoma (LTG).

PATIENTS AND METHODS

Glaucoma was defined as glaucomatous optic neuropathy and reproducible visual field defects. Patients were classified as having LTG if untreated intraocular pressure was ≤21 mm Hg on 2 different occasions. Only eyes with early glaucoma (mean deviation <-6 dB) were included. All patients underwent spectral-domain optical coherence tomography (SDOCT) imaging.

RESULTS

A total of 56 normal subjects, 64 HTG patients, and 35 LTG patients were enrolled. Overall, after adjusting for mean deviation and age, the average pRNFL thickness in eyes with LTG was 18.7 µm thinner than in eyes with HTG (17% difference, P<0.01). In the HTG group, no significant difference was found between areas under the receiver operating characteristic curve (AUCs) for average GCC and average pRNFL thicknesses (0.77 vs. 0.68, P=0.06). In the LTG group, average pRNFL thickness had a significantly larger AUC compared with average GCC thickness (0.95 vs. 0.81, P<0.001). Comparing AUCs between HTG and LTG groups, although the average GCC had similar AUCs in both groups (P=0.47), the average pRNFL thickness had a significantly larger AUC in the LTG group (P<0.001).

CONCLUSIONS

In eyes with early glaucoma, the pRNFL thickness scan seems to be a more accurate SDOCT protocol to identify those with LTG compared with the GCC thickness scan.

Endograft Sizing for Endovascular Aortic Repair and Incidence of Endoleak Type 1A

Objective

In endovascular aortic aneurysm repair (EVAR), proximal type 1A endoleaks can occur as a result of hostile neck anatomy or over- or undersizing of the endograft. As the current standard is based on the diameter or average of the short and long axes in a central lumen reconstruction image, it can falter in irregularly shaped aortic necks. An alternative method is circumference-based, therefore minimizing the measurement error. In this study we aimed to assess the degree of discrepancy between both methods and the association of this discrepancy with the occurrence of endoleak type 1A.

Methods

All patients with early (<30 days post-operative) endoleak type 1A after elective EVAR at our center between 2004 and 2016 were identified for a retrospective case-control study. Control patients were matched based on hostile neck anatomy, such as calcification, thrombus, reverse taper, and β-angulation. The aortic neck diameter was measured using the traditional, diameter-based method as well as an alternative method, based on the circumference of the aortic neck.

Results

In 482 EVAR patients, 18 early endoleak type 1A cases were found (3.9%). After exclusion, 12 cases remained and 48 matching controls were found. No significant differences were found between the two measuring methods at any level below the renal arteries. The inter-observer variability was significant for the D(mean) (0.4 ± 1.69 mm, P = .02) and was larger than the D(circ) method (-0.1 ± 1.03 mm, P = .35). In only four out of 12 cases the endograft size was 10–20% larger than the D(mean) and D(circ) measurements. The differences between the diameter of the D(mean) and D(circ) and the chosen endograft were smaller for the case group (-8 ± 25.6% and -7 ± 24%) than for the control group. (-12.4 ± 12.4% and -11 ± 10.7%).

Conclusion

The difference between the D(mean) and D(circ) methods for aortic neck measurement was not large enough to play a significant role in the incidence of endoleak type 1A. Inadequate oversizing and considerable β-angulation of the aortic neck may have been the cause of endoleak type 1A in this population. Robust and well-investigated sizing methods are paramount for accurate endograft sizing and prevention of endoleak type 1A. Therefore the lack of studies in this field and a sizeable inter-observer variability do not justify the widespread reliance on the traditional diameter-based methods for endograft sizing.

Characteristics and Outcome of Patients With AIDS in Dutch ICUs Between 1997 and 2014

OBJECTIVE

Knowledge on characteristics and outcome of ICU patients with AIDS is highly limited. We aimed to determine the main reasons for admission and outcome in ICU patients with AIDS and trends over time therein.

DESIGN

A retrospective study within the Dutch National Intensive Care Evaluation registry.

SETTING

Dutch ICUs.

PATIENTS

We used data collected between 1997 and 2014. Characteristics of patients with AIDS were compared with ICU patients without AIDS, matched for age, sex, admission type, and admission year. Joinpoint regression analysis was applied to study trends over time.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We included 1,127 patients with AIDS and 4,479 matched controls. The main admission diagnoses of patients with AIDS were respiratory infection (28.6%) and sepsis (16.9%), which were less common in controls (7.7% and 7.5%, respectively; both p < 0.0001). Patients with AIDS had increased severity of illness and in-hospital mortality (28.2% vs 17.8%; p < 0.0001) compared with controls, which was associated with a higher rate of infections at admission in patients with AIDS (58.4% vs 25.5%). Over time, the proportion of patients with AIDS admitted with an infection decreased (75% in 1999 to 56% in 2013). Mortality declined in patients with AIDS (39% in 1999 to 16% in 2013), both in patients with or without an infection. Mortality also declined in matched controls without AIDS, but to a lesser extent.

CONCLUSION

Infections are still the main reason for ICU admission in patients with AIDS, but their prevalence is declining. Outcome of patients with AIDS continued to improve during a time of widespread availability of combination antiretroviral therapy, and mortality is reaching levels similar to ICU patients without AIDS.

Use of Extended Characteristics of Locomotion and Feeding Behavior for Automated Identification of Lame Dairy Cows

This study was carried out to detect differences in locomotion and feeding behavior in lame (group L; n = 41; gait score ≥ 2.5) and non-lame (group C; n = 12; gait score ≤ 2) multiparous Holstein cows in a cross-sectional study design. A model for automatic lameness detection was created, using data from accelerometers attached to the hind limbs and noseband sensors attached to the head. Each cow’s gait was videotaped and scored on a 5-point scale before and after a period of 3 consecutive days of behavioral data recording. The mean value of 3 independent experienced observers was taken as a definite gait score and considered to be the gold standard. For statistical analysis, data from the noseband sensor and one of two accelerometers per cow (randomly selected) of 2 out of 3 randomly selected days was used. For comparison between group L and group C, the T-test, the Aspin-Welch Test and the Wilcoxon Test were used. The sensitivity and specificity for lameness detection was determined with logistic regression and ROC-analysis. Group L compared to group C had significantly lower eating and ruminating time, fewer eating chews, ruminating chews and ruminating boluses, longer lying time and lying bout duration, lower standing time, fewer standing and walking bouts, fewer, slower and shorter strides and a lower walking speed. The model considering the number of standing bouts and walking speed was the best predictor of cows being lame with a sensitivity of 90.2% and specificity of 91.7%. Sensitivity and specificity of the lameness detection model were considered to be very high, even without the use of halter data. It was concluded that under the conditions of the study farm, accelerometer data were suitable for accurately distinguishing between lame and non-lame dairy cows, even in cases of slight lameness with a gait score of 2.5.

Class-imbalanced subsampling lasso algorithm for discovering adverse drug reactions

Background All methods routinely used to generate safety signals from pharmacovigilance databases rely on disproportionality analyses of counts aggregating patients' spontaneous reports. Recently, it was proposed to analyze individual spontaneous reports directly using Bayesian lasso logistic regressions. Nevertheless, this raises the issue of choosing an adequate regularization parameter in a variable selection framework while accounting for computational constraints due to the high dimension of the data. Purpose Our main objective is to propose a method, which exploits the subsampling idea from Stability Selection, a variable selection procedure combining subsampling with a high-dimensional selection algorithm, and adapts it to the specificities of the spontaneous reporting data, the latter being characterized by their large size, their binary nature and their sparsity. Materials and method Given the large imbalance existing between the presence and absence of a given adverse event, we propose an alternative subsampling scheme to that of Stability Selection resulting in an over-representation of the minority class and a drastic reduction in the number of observations in each subsample. Simulations are used to help define the detection threshold as regards the average proportion of false signals. They are also used to compare the performances of the proposed sampling scheme with that originally proposed for Stability Selection. Finally, we compare the proposed method to the gamma Poisson shrinker, a disproportionality method, and to a lasso logistic regression approach through an empirical study conducted on the French national pharmacovigilance database and two sets of reference signals. Results Simulations show that the proposed sampling strategy performs better in terms of false discoveries and is faster than the equiprobable sampling of Stability Selection. The empirical evaluation illustrates the better performances of the proposed method compared with gamma Poisson shrinker and the lasso in terms of number of reference signals retrieved.

Strategies for recruiting representative samples of Asian Americans for a population-based case-control study

BACKGROUND

Data are limited on effective methods for recruiting persons, especially from ethnically diverse populations, into population-based studies. The goal of this study was to evaluate the variation among and representativeness of controls identified using multiple methods for a population-based case-control study of breast cancer among Asian Americans, Native Hawaiians and Pacific Islanders (AANHPIs) in the San Francisco Bay Area.

METHODS

We used a unique combination of targeted recruitment strategies, including address-based sampling, community-based methods, and internet-based and media-based approaches for recruiting controls, frequency matched on age and ethnicity to a population-based sample of cases. To characterise the participating controls, we compared the distribution of sociodemographic characteristics and cancer risk factors between recruitment sources using χ(2) tests. To ensure that the controls we recruited were representative of the underlying at-risk population, we compared characteristics of the controls, by ethnicity and in aggregate, to data from the California Health Interview Survey (CHIS), and adjusted the relative mix of recruitment strategies throughout the study as needed to achieve representativeness.

RESULTS

As expected, controls (n=483) recruited by any single method were not representative. However, when aggregated across methods, controls were largely representative of the underlying source population, as characterised by CHIS, with regard to the characteristics under study, including nativity, education, marital status and body mass index.

CONCLUSIONS

A multimode approach using targeted recruitment strategies is an effective and feasible alternative to using a single recruitment method in identifying a representative, diverse control sample for population-based studies.

Risk Factors for Infection After Rotator Cuff Repair

PURPOSE

To identify risk factors for infection after rotator cuff repair. We hypothesized that patient characteristics and surgical technique would affect the rate of infection.

METHODS

The records of 1,824 rotator cuff repairs performed by a single surgeon from 1995 to 2010 were reviewed retrospectively. Fourteen patients had an early deep postoperative wound infection that was treated with surgical irrigation and debridement. One hundred eighty-five control patients who were treated with rotator cuff repair and did not develop an infection were selected randomly for comparison and statistical analysis. Data regarding preoperative and intraoperative risk factors for infection were recorded, and a multiple logistic regression was conducted to investigate predictors of infection.

RESULTS

The infection rate was 0.77% (14/1,822). On average 2.1 (range 1 to 4) surgical debridements were performed in addition to treatment with intravenous antibiotics. Patients who had open or miniopen rotator cuff repair had a significantly greater risk of acute postoperative infection (odds ratio [OR] = 8.63, P = .002). Seventy-nine percent of the patients in the infection group had an open or miniopen repair, whereas only 28% of the control group had an open or miniopen repair. Male patients also had a significantly greater risk of acute postoperative infection (OR = 9.52, P = .042). A total of 92% of the infection patients were male compared with 58% of the control group. In addition, as body mass index increased there was a reduction in the odds of infection (OR = 0.81, P = .023).

CONCLUSIONS

The results of this case control study demonstrate that open or miniopen surgical technique and male sex are significant risk factors for infection after rotator cuff repair. In our study, arthroscopic rotator cuff repair reduced the risk of infection compared with open techniques.

LEVEL OF EVIDENCE

Level IV.

Drug-induced liver injury: results from the hospital-based Berlin Case-Control Surveillance Study

AIM

Drug-induced liver injury (DILI) is often responsible for acute liver failure, drug withdrawal, boxed warnings or drug non-approval. Therefore, we conducted a case-control study to determine the hepatotoxic risk of a wide range of drugs.

METHODS

The Berlin Case-Control Surveillance Study FAKOS included all 51 Berlin hospitals in a hospital network. Between 2002 and 2011, 198 patients with acute idiopathic hepatitis, 377 inpatient controls and 708 outpatient controls were ascertained. Case patients were thoroughly validated using anamnestic, clinical, laboratory and histological data. Drug exposure was obtained in a face-to-face interview. A possible drug aetiology was assessed in individual patients by applying the updated Council for International Organizations of Medical Sciences (CIOMS) scale. Drug risks were further quantified [odds ratios (OR) with 95% confidence intervals (CI)] in a case-control design with unconditional logistic regression analysis. Drug intake in the last 28 days before index date was considered for the analysis.

RESULTS

The study corroborated hepatotoxic risks for a number of drugs, including phenprocoumon (OR 3.3, 95% CI 1.5, 6.7), amiodarone (OR 5.5, 95% CI 1.3, 21.2), clozapine (OR 34.6, 95% CI 2.8, 824.9) and flupirtine (OR 40.2, 95% CI 5.5, 856.9). Increased risks were also suggested for less commonly reported substances such as angiotensin II receptor blockers, atypical antipsychotics and for biperiden, a drug never before reported to be hepatotoxic.

CONCLUSIONS

Our study identified a large number of drugs as possible causes of hepatotoxicity. The observed risk for seldom reported substances highlights the need for further post-authorization safety studies not exclusively focusing on drugs already labelled as potentially hepatotoxic.

Risk factors for the development of colorectal carcinoma: A case control study from South India

AIM: To study the association of colorectal carcinoma (CRC) with diet, smoking, alcohol, physical activity, body mass index, family history and diabetes.

METHODS: All consecutive patients with CRC confirmed by histopathology diagnosis were included. Age (± 5 years) and gender matched controls were selected among the patients admitted in surgery ward for various conditions without any co-existing malignancy. Food frequency questionnaire (FFQ) was developed and validated after pretesting by investigator trained in data collection techniques. Cases and controls were interviewed ensuring privacy, in similar interview setting, with same duration of time for both cases and controls without any leading question. Biological variables like family history of CRC in first degree relatives, history of diabetes mellitus; behavioral factors like tobacco use both smoking and smokeless form, alcohol consumption and physical activity were recorded. Dietary details were recorded using a FFQ consisting 29 food items with seven categories. Analysis was done using appropriate statistical methods.

RESULTS: Ninety-four histopathologically confirmed cases of CRC and equal number of age and gender matched controls treated over a period of two years were studied. Age distribution, mean age, male to female ratio, education level and socioeconomic status were similar in cases and controls. Intake of food items was categorized into tertile due to skewed distribution of subjects as per recommended cut off for consumption of food item. On univariate analysis red meat [OR = 7.4 (2.935-18.732)], egg [OR = 5.1 (2.26-11.36)], fish, fried food and oil consumption were found to be risk factors for CRC. On multivariate analysis red meat consumption of more than 2-3 times a month (OR = 5.4; 95%CI: 1.55-19.05) and egg consumption of more than 2-3 times a week (OR = 3.67; 95%CI: 1.23-9.35) were found to be independent risk factors for the development of CRC.

CONCLUSION: Egg and red meat consumption found to be independent risk factors for CRC. Smoking, alcohol, physical activity and family history were not associated with increased risk.

Pediatric Inflammatory Bowel Disease Among South Asians Living in British Columbia, Canada: A Distinct Clinical Phenotype

BACKGROUND

Inflammatory bowel disease (IBD) incidence is increasing among low-risk populations. This study examined a cohort of Canadian South Asian (SA) children with IBD to determine if their disease course differed from non-SA (NSA) children.

METHODS

Children of SA ethnicity diagnosed with IBD between 1997 and 2012 were identified and compared with NSA children. Data on duration and the type of presenting symptoms, disease phenotype, corticosteroid exposure (CS), exclusive enteral nutrition use, time to commencement of immunomodulator (IM), biologic therapy, and surgical intervention were extracted.

RESULTS

Overall, 160 SA children were identified and compared with 783 NSA patients (Crohn's disease [CD]: 44% versus 72%; ulcerative colitis [UC]: 43% versus 21%; IBD-Unclassified: 13% versus 7%; P < 0.001). SA patients were predominantly second-generation Canadians (92%) and had shorter symptom duration (2 versus 4 months; P < 0.001). SA CD patients were less likely to have a parent with IBD (1% versus 14%; P = 0.003). SA patients had more extensive colonic disease (CD: 55% versus 35%; P = 0.005; UC: 77% versus 58%; P = 0.006); SA CD patients presented with more complicated disease (B2/B3: 39% versus 27%; P = 0.006) and UC patients presented with more severe disease (49% versus 23%; P < 0.001). In SA CD patients, CS use was higher (70% versus 58%; P = 0.045), and IM and biologic therapy were commenced earlier (P = 0.027; P = 0.047). SA UC patients were more likely to need CS and IM (P = 0.024; P < 0.001).

CONCLUSIONS

These data describe an ethnically unique clinical phenotype, where SA children have a higher proportion of UC, shorter symptom duration, more extensive colonic disease, and are more likely to require earlier escalation of therapy.

Psychological disorders and oral lichen planus: matched case-control study and literature review

OBJECTIVE

Oral lichen planus (OLP) may be linked to psychological disorders. This study investigated psychological factors associated with OLP.

METHODS

A case-control study with incident OLP case patients and age-gender-socio-economic status-matched controls, recruited from among relatives, accompanying persons, and departmental staff, investigated psychological traits using the Psychological General Well-Being Index-Short form. Common factor analysis was used to generate a set of psychological dimensions. The association between these dimensions and OLP adjusted for confounders (education, number of lifetime sexual partners, drinking-smoking) and interactions was assessed through conditional logistic regression and odds ratios (OR) were estimated.

RESULTS

A total of 67 case-control pairs were recruited. Psychological dimensions generated were: dimension-1 (anxiety, low vitality), dimension-2 (negative well-being, low vitality), dimension-3 (depressed mood, low self-control). The ORs for OLP were, dimension-1, 1.0 (95% confidence interval -95CI, 0.3-2.6); dimension-2, 0.5 (95CI, 0.2-1.2); dimension-3, 4.8 (95CI, 1.8-12.9). Dimension-3 was highly associated with mild, but not associated with severe, OLP. Literature searching provided 21 studies, with anxiety and depression principally associated with OLP.

CONCLUSIONS

Depressed mood and low self-control were highly associated with OLP, particularly the reticular-papular forms. These traits could have a causative role in OLP development-progression, but further investigations are necessary.