Composite Measures of Individual and Area-Level Socio-Economic Status Are Associated with Visual Impairment in Singapore

Purpose

To investigate the independent relationship of individual- and area-level socio-economic status (SES) with the presence and severity of visual impairment (VI) in an Asian population.

Methods

Cross-sectional data from 9993 Chinese, Malay and Indian adults aged 40–80 years who participated in the Singapore Epidemiology of eye Diseases (2004–2011) in Singapore. Based on the presenting visual acuity (PVA) in the better-seeing eye, VI was categorized into normal vision (logMAR≤0.30), low vision (logMAR>0.30<1.00), and blindness (logMAR≥1.00). Any VI was defined as low vision/blindness in the PVA of better-seeing eye. Individual-level low-SES was defined as a composite of primary-level education, monthly income<2000 SGD and residing in 1 or 2-room public apartment. An area-level SES was assessed using a socio-economic disadvantage index (SEDI), created using 12 variables from the 2010 Singapore census. A high SEDI score indicates a relatively poor SES. Associations between SES measures and presence and severity of VI were examined using multi-level, mixed-effects logistic and multinomial regression models.

Results

The age-adjusted prevalence of any VI was 19.62% (low vision = 19%, blindness = 0.62%). Both individual- and area-level SES were positively associated with any VI and low vision after adjusting for confounders. The odds ratio (95% confidence interval) of any VI was 2.11(1.88–2.37) for low-SES and 1.07(1.02–1.13) per 1 standard deviation increase in SEDI. When stratified by unilateral/bilateral categories, while low SES showed significant associations with all categories, SEDI showed a significant association with bilateral low vision only. The association between low SES and any VI remained significant among all age, gender and ethnic sub-groups. Although a consistent positive association was observed between area-level SEDI and any VI, the associations were significant among participants aged 40–65 years and male.

Conclusion

In this community-based sample of Asian adults, both individual- and area-level SES were independently associated with the presence and severity of VI.     

Patient Understanding of Discharge Instructions for Home Diabetes Self-Management and Risk for Hospital Readmission and Emergency Department Visits

ObjectiveThe primary objective of this study was to examine the patient comprehension of diabetes self-management instructions provided at hospital discharge as an associated risk of readmission.MethodsNoncritically ill patients with diabetes completed patient comprehension questionnaires (PCQ) within 48 hours of discharge. PCQ scores were compared among patients with and without readmission or emergency department (ED) visits at 30 and 90 days. Glycemic measures 48 hours preceding discharge were investigated. Diabetes Early Readmission Risk Indicators (DERRIs) were calculated for each patient.ResultsOf 128 patients who completed the PCQ, scores were similar among those with 30-day (n = 31) and 90-day (n = 54) readmission compared with no readmission (n = 72) (79.9 ± 14.4 vs 80.4 ± 15.6 vs 82.3 ± 16.4, respectively) or ED visits. Clarification of discharge information was provided for 47 patients. PCQ scores of 100% were achieved in 14% of those with and 86% without readmission at 30 days (P = .108). Of predischarge glycemic measures, glycemic variability was negatively associated with PCQ scores (P = .035). DERRIs were significantly higher among patients readmitted at 90 days but not 30 days.ConclusionThese results demonstrate similar PCQ scores between patients with and those without readmission or ED visits despite the need for corrective information in many patients. Measures of glycemic variability were associated with PCQ scores but not readmission risk. This study validates DERRI as a predictor for readmission at 90 days.     

Continuity in a VA Patient-Centered Medical Home Reduces Emergency Department Visits

Background

One major goal of the Patient-Centered Medical Home (PCMH) is to improve continuity of care between patients and providers and reduce the utilization of non-primary care services like the emergency department (ED).

Objective

To characterize continuity under the Veterans Health Administration’s PCMH model – the Patient Aligned Care Team (PACT), at one large Veterans Affair’s (VA’s) primary care clinic, determine the characteristics associated with high levels of continuity, and assess the association between continuity and ED visits.

Design

Retrospective, observational cohort study of patients at the West Haven VA (WHVA) Primary Care Clinic from March 2011 to February 2012.

Patients

The 13,495 patients with established care at the Clinic, having at least one visit, one year before March 2011.

Main Measures

Our exposure variable was continuity of care –a patient seeing their assigned primary care provider (PCP) at each clinic visit. The outcome of interest was having an ED visit.

Results

The patients encompassed 42,969 total clinic visits, and 3185 (24%) of them had 15,458 ED visits. In a multivariable logistic regression analysis, patients with continuity of care – at least one visit with their assigned PCP – had lower ED utilization compared to individuals without continuity (adjusted odds ratio [AOR] 0.54; 95% CI: 0.41, 0.71), controlling for frequency of primary care visits, comorbidities, insurance, distance from the ED, and having a trainee PCP assigned. Likewise, the adjusted rate of ED visits was 544/1000 person-year (PY) for patients with continuity vs. 784/1000 PY for patients without continuity (p = 0.001). Compared to patients with low continuity (<33% of visits), individuals with medium (33–50%) and high (>50%) continuity were less likely to utilize the ED.

Conclusions

Strong continuity of care is associated with decreased ED utilization in a PCMH model and improving continuity may help reduce the utilization of non-primary care services.     

Hospital Readmissions of Patients with Heart Failure: The Impact of Hospital and Primary Care Organizational Factors in Northern Italy

BackgroundPrimary health care is essential for an appropriate management of heart failure (HF), a disease which is a major clinical and public health issue and a leading cause of hospitalization. The aim of this study was to evaluate the impact of different organizational factors on readmissions of patients with HF.MethodsThe study population included elderly resident in the Local Health Authority of Bologna (Northern Italy) and discharged with a diagnosis of HF from January to December 2010. Unplanned hospital readmissions were measured in four timeframes: 30 (short-term), 90 (medium-term), 180 (mid-long-term), and 365 days (long-term). Using multivariable multilevel Poisson regression analyses, we investigated the association between readmissions and organizational factors (discharge from a cardiology department, general practitioners’ monodisciplinary organizational arrangement, and implementation of a specific HF care pathway).ResultsThe 1873 study patients had a median age of 83 years (interquartile range 77–87) and 55.5% were females; 52.0% were readmitted to the hospital for any reason after a year, while 20.1% were readmitted for HF. The presence of a HF care pathway was the only factor significantly associated with a lower risk of readmission for HF in the short-, medium-, mid-long- and long-term period (short-term: IRR [incidence rate ratio]=0.57, 95%CI [confidence interval]=0.35–0.92; medium-term: IRR=0.70, 95%CI=0.51–0.96; mid-long-term: IRR=0.79, 95%CI=0.64–0.98; long-term: IRR=0.82, 95%CI=0.67–0.99), and with a lower risk of all-cause readmission in the short-term period (IRR=0.73, 95%CI=0.57–0.94).ConclusionOur study shows that the HF care specific pathway implemented at the primary care level was associated with lower readmission rate for HF in each timeframe, and also with lower readmission rate for all causes in the short-term period. Our results suggest that the engagement of primary care professionals starting from the early post-discharge period may be relevant in the management of patients with HF.     

Sustained Elevation of Resistin,NGAL and IL-8 Are Associated with Severe Sepsis/Septic Shock in the Emergency Department

Objective

To identify biomarkers which distinguish severe sepsis/septic shock from uncomplicated sepsis in the Emergency Department (ED).

Methods

Patients with sepsis underwent serial blood sampling, including arrival in the ED and up to three subsequent time points over the first 24 hours. Messenger RNA (mRNA) levels of 13 genes representing arms of the innate immune response, organ dysfunction or shock were measured in peripheral blood leucocytes using quantitative PCR, and compared with healthy controls. Serum protein concentrations of targets differentially expressed between uncomplicated sepsis and severe sepsis/septic shock were then measured at each time point and compared between the two patient groups.

Results

Of 27 participants (median age 66 years, (IQR 35, 78)), 10 had uncomplicated sepsis and 17 had sepsis with organ failure (14 septic shock; 3 had other sepsis-related organ failures). At the time of first sample collection in the ED, gene expression of Interleukin (IL)-10 and Neutrophil Gelatinase Associated Lipocalin (NGAL) were significantly higher in severe sepsis than uncomplicated sepsis. Expression did not significantly change over time for any target gene. Serum concentrations of IL-6, IL-8, IL-10, NGAL and Resistin were significantly higher in severe sepsis than uncomplicated sepsis at the time of first sample collection in the ED, but only IL-8, NGAL and Resistin were consistently higher in severe sepsis compared to uncomplicated sepsis at all time points up to 24 h after presentation.

Conclusions

These mediators, produced by both damaged tissues and circulating leukocytes, may have important roles in the development of severe sepsis. Further work will determine whether they have any value, in addition to clinical risk parameters, for the early identification of patients that will subsequently deteriorate and/or have a higher risk of death.     

The Relationship between Same-Day Access and Continuity in Primary Care and Emergency Department Visits

We examined how emergency department (ED) visits for potentially preventable, mental health, and other diagnoses were related to same-day access and provider continuity in primary care using administrative data from 71,296 patients in 22 VHA clinics over a three-year period. ED visits were categorized as non-emergent; primary care treatable; preventable; not preventable; or mental health-related. We conducted multi-level regression models adjusted for patient and clinic factors. More same-day access significantly predicted fewer non-emergent and primary care treatable ED visits while continuity was not significantly related to any type of ED visit. Neither measure was related to ED visits for mental health problems.     

Factors Associated with the Occurrence of Cardiac Arrest after Emergency Tracheal Intubation in the Emergency Department

Objectives

Emergency tracheal intubation has achieved high success and low complication rates in the emergency department (ED). The objective of this study was to evaluate the incidence of post-intubation CA and determine the clinical factors associated with this complication.

Methods

A matched case-control study with a case to control ratio of 1∶3 was conducted at an urban tertiary care center between January 2007 and December 2011. Critically ill adult patients requiring emergency airway management in the ED were included. The primary endpoint was post-intubation CA, defined as CA within 10 minutes after tracheal intubation. Clinical variables were compared between patients with post-intubation CA and patients without CA who were individually matched based on age, sex, and pre-existing comorbidities.

Results

Of 2,403 patients who underwent emergency tracheal intubation, 41 patients (1.7%) had a post-intubation CA within 10 minutes of the procedure. The most common initial rhythm was pulseless electrical activity (78.1%). Patients experiencing CA had higher in-hospital mortality than patients without CA (61.0% vs. 30.1%; p<0.001). Systolic hypotension prior to intubation, defined as a systolic blood pressure ≤90 mmHg, was independently associated with post-intubation CA (OR, 3.67 [95% CI, 1.58–8.55], p = 0.01).

Conclusion

Early post-intubation CA occurred with an approximate 2% frequency in the ED. Systolic hypotension before intubation is associated with this complication, which has potentially significant implications for clinicians at the time of intubation.     

The Impact of Heat on an Emergency Department in Italy: Attributable Visits among Children,Adults, and the Elderly during the Warm Season

Introduction

Recent studies suggest that heat is associated with an increase in the number of ambulance calls and emergency department visits. We investigated the association between heat and daily number of emergency department visits at the University Hospital of Verona during the warm seasons 2011–2012 and we assessed the magnitude of the impact in terms of attributable events, focusing on the role of age and triage codification.

Materials and methods

We used a Poisson model to analyse the association between daily number of visits and daily mean apparent temperature, accounting for air pollution level and seasonality. The analyses were stratified by age group and were performed both on the total number of emergency department visits and on the subsample of high-priority visits. Impact estimates were obtained only for this subsample, using a Monte Carlo approach to account for sampling variability. Number of attributable events and attributable community rate were calculated.

Results

We found a positive and immediate association between event occurrence and mean apparent temperatures exceeding a threshold located around 28–29°C. The estimated percent change in the total number of visits per 1°C increase of exposure above the threshold was equal to 3.75 (90% CI: 3.01; 4.49). Focusing only on high-priority visits, the estimated percent change was larger and the greatest effect was among children. We estimated that apparent temperatures above the threshold were responsible for 1177 high-priority visits during the study period. Due to the record high temperatures observed in 2012 in Italy and in Europe, the impact in 2012 was much larger than in 2011, and consisted in 34 high-priority visits every 10000 children, 30 every 10000 people aged 15–64, and 38 every 10000 people aged 65 and over.

Discussion

Our results indicate that heat affects not only the elderly, but also children and non-elderly adults, stressing the need for developing public health preparedness plans for the entire community.     

Associations between Extending Access to Primary Care and Emergency Department Visits: A Difference-In-Differences Analysis

BackgroundHealth services across the world increasingly face pressures on the use of expensive hospital services. Better organisation and delivery of primary care has the potential to manage demand and reduce costs for hospital services, but routine primary care services are not open during evenings and weekends.Extended access (evening and weekend opening) is hypothesized to reduce pressure on hospital services from emergency department visits. However, the existing evidence-base is weak, largely focused on emergency out-of-hours services, and analysed using a before-and after-methodology without effective comparators.ConclusionsThe study found that extending access was associated with a reduction in emergency department visits in the first 12 months. The results of the research have already informed the decision by National Health Service England to extend primary care access across Greater Manchester from 2016. However, further evidence is needed to understand whether extending primary care access is cost-effective and sustainable.     

Pre-Emergency-Department Care-Seeking Patterns Are Associated with the Severity of Presenting Condition for Emergency Department Visit and Subsequent Adverse Events: A Timeframe Episode Analysis

Background

Many patients treated in Emergency Department (ED) visits can be treated at primary or urgent care sectors, despite the fact that a number of ED visitors seek other forms of care prior to an ED visit. However, little is known regarding how the pre-ED activity episodes affect ED visits.

Objectives

We investigated whether care-seeking patterns involve the use of health care services of various types prior to ED visits and examined the associations of these patterns with the severity of the presenting condition for the ED visit (EDVS) and subsequent events.

Methods

This retrospective observational study used administrative data on beneficiaries of the universal health care insurance program in Taiwan. The service type, treatment capacity, and relative diagnosis were used to classify pre-ED visits into 8 care types. Frequent pattern analysis was used to identify sequential care-seeking patterns and to classify 667,183 eligible pre-ED episodes into patterns. Generalized linear models were developed using generalized estimating equations to examine the associations of these patterns with EDVS and subsequent events.

Results

The results revealed 17 care-seeking patterns. The EDVS and likelihood of subsequent events significantly differed among patterns. The ED severity index of patterns differ from patterns seeking directly ED care (coefficients ranged from -0.05 to 0.13), and the odds-ratios for the likelihood of subsequent ED visits and hospitalization ranged from 1.18 to 1.86 and 1.16 to 2.84, respectively.

Conclusions

The pre-ED care-seeking patterns differ in severity of presenting condition and subsequent events that may represent different causes of ED visit. Future health policy maker may adopt different intervention strategies for targeted population to reduce unnecessary ED visit effectively.     

综合医院急诊科患者躯体化症状对其住院时间和住院费用的影响

目的:探讨躯体化症状对综合医院急诊科住院患者住院时间和住院费用的影响及躯体化症状自评量表在急诊科住院患者中的应用价值。方法:采用躯体化症状自评量表对100例急诊科住院患者进行心理状态评估,评分≤40分为低分组,40分为高分组,比较两组的一般情况及住院时间和费用,并对住院费用和时间的影响因素进行多因素分析。结果:100例患者中,SSS得分≤40分共73例,40分共27例,两组间年龄、性别分布比较有统计学差异,受教育程度、职业和病程等方面差异均无统计学意义。高分组患者年龄偏大(71.15±14.42 vs 61.62±14.66)岁,女性比例较高(59.2%vs 32.8%),住院天数较长(16.30±3.81 vs13.56±5.64天),住院费用较高(17922.55±1966.64 vs 14252.13±8655.71元)。多元回归分析结果显示住院时间与费用与患者的年龄、性别及躯体化症状有相关性。结论:躯体化症状是综合性医院急诊科住院病人常见症状,与年龄及性别相关,可能延长患者的住院时间和住院费用。躯体化症状自评量表具有较好的信度和效度,可应用于综合医院住院患者心理症状的筛查。     

Drinking Water Turbidity and Emergency Department Visits for Gastrointestinal Illness in New York City, 2002-2009

Background

Studies have examined whether there is a relationship between drinking water turbidity and gastrointestinal (GI) illness indicators, and results have varied possibly due to differences in methods and study settings.

Objectives

As part of a water security improvement project we conducted a retrospective analysis of the relationship between drinking water turbidity and GI illness in New York City (NYC) based on emergency department chief complaint syndromic data that are available in near-real-time.

Methods

We used a Poisson time-series model to estimate the relationship of turbidity measured at distribution system and source water sites to diarrhea emergency department (ED) visits in NYC during 2002-2009. The analysis assessed age groups and was stratified by season and adjusted for sub-seasonal temporal trends, year-to-year variation, ambient temperature, day-of-week, and holidays.

Results

Seasonal variation unrelated to turbidity dominated (~90% deviance) the variation of daily diarrhea ED visits, with an additional 0.4% deviance explained with turbidity. Small yet significant multi-day lagged associations were found between NYC turbidity and diarrhea ED visits in the spring only, with approximately 5% excess risk per inter-quartile-range of NYC turbidity peaking at a 6 day lag. This association was strongest among those aged 0-4 years and was explained by the variation in source water turbidity.

Conclusions

Integrated analysis of turbidity and syndromic surveillance data, as part of overall drinking water surveillance, may be useful for enhanced situational awareness of possible risk factors that can contribute to GI illness. Elucidating the causes of turbidity-GI illness associations including seasonal and regional variations would be necessary to further inform surveillance needs.     

Study on the Factors Associated with Postpartum Visits in Rural China

Background

Postpartum visits (PPVs) have been advocated as a way to improve health outcomes for mothers and their infants, but the rate of PPVs is still low in rural China. This study aims to investigate the utilization of PPVs and to explore the factors associated with PPVs in rural China. Parity is the most concerned factor in this study.

Methods

A cross-sectional household survey was performed in two counties of Zhejiang province. Questions include socio-economic, health services and women''s delivery data. Chi-square tests and multivariate logistic regression analyses were performed to identify factors associated with PPVs.

Results

223 women who had a delivery history in the recent five years were enrolled in analyses. 173 (78%) of them were primiparous. Among the primiparous women, 43 (25%) had not received any PPVs. The majority, 27 (55%) of the 49 multiparous women, had not received any PPVs. Multiparous women were less likely to receive PPVs than primiparous women. Among 223 puerperal women, 47 (21%) had been compensated for delivery fee expenses. Women who received compensation were found to be more likely to receive standard (at least 3) PPVs.

Conclusions

It was found that women with “second babies” were less likely to use PPVs. This could be an unintended consequence of the “one-child policy”, due to fear that contact with public health facilities could result in sanctions. This phenomenon should be taken seriously by government in order to improve the health of babies and their mothers. Financial compensation for delivery fee charges can improve the use of PPVs, thus free-of-charge delivery should be promoted.     

Sunny Holidays before and after Melanoma Diagnosis Are Respectively Associated with Lower Breslow Thickness and Lower Relapse Rates in Italy

Background

Previous studies have reported an association between sun exposure and improved cutaneous melanoma (CM) survival. We analysed the association of UV exposure with prognostic factors and outcome in a large melanoma cohort.

Methods

A questionnaire was given to 289 (42%) CM patients at diagnosis (Group 1) and to 402 CM patients (58%) during follow-up (Group 2). Analyses were carried out to investigate the associations between sun exposure and melanoma prognostic factors and survival.

Results

Holidays in the sun two years before CM diagnosis were significantly associated with lower Breslow thickness (p=0.003), after multiple adjustment. Number of weeks of sunny holidays was also significantly and inversely associated with thickness in a dose-dependent manner (p=0.007). However when stratifying by gender this association was found only among women (p=0.0004) the risk of CM recurrence in both sexes was significantly lower in patients (n=271) who had holidays in the sun after diagnosis, after multiple adjustment including education: HR=0.30 (95%CI:0.10-0.87; p=0.03) conclusions: Holidays in the sun were associated with thinner melanomas in women and reduced rates of relapse in both sexes. However, these results do not prove a direct causal effect of sun exposure on survival since other confounding factors, such as vitamin D serum levels and socio-economic status, may play a role. Other factors in sun seeking individuals may also possibly affect these results.     

Elevated Steady State WBC and Platelet Counts Are Associated with Frequent Emergency Room Use in Adults with Sickle Cell Anemia

Introduction

Sickle cell anemia has many sequelae that result in emergency department (ED) use, but a minority of patients with sickle cell disease are frequent utilizers and make up the majority of ED visits. If patients who are likely to be frequent ED can be identified in steady state, they can be treated with disease modifying agents in an attempt to reduce ED use frequency. We sought to identify steady state markers for frequent ED use.

Methods

We identified all patients with SS/Sβ0 seen at our facilities in 2012. Health care utilization over the entire year was calculated and ED visit numbers categorized as either 0–1, 2–5, or 6 or more visits a year. Steady state and acutely active laboratory parameters were collected and analyzed using analysis of variance models and odds ratios.

Results

432 adult sickle cell patients were identified, ages 18–87, 54% female, and 38% had been prescribed hydroxyurea. Of the 432 patients,192 had 0–1 visits in the year, 144 had 2–5 visits in the year, and 96 had >6 visits for a total of 2259 visits. Those who had >6 visits accounted for 1750 (77%) of the total visits for the year. When steady state laboratory markers were examined, each additional 50x109/L platelets was associated with 22% greater risk (p < .001); each 1x109/L of WBC was associated with 11% greater risk (p = .003), and each 1g/dL Hb was associated with 23% lower risk (p = .007) of >6 ED visits/year. We did not observe a relationship between baseline HbF, LDH or reticulocyte count with >6 ED visits.

Conclusion

Patients with elevated white blood cell counts, elevated platelet counts, and low hemoglobin levels exhibited higher risk for frequent ED utilization and could be candidates for early and aggressive therapy with disease modifying agents.     

Prevalence and Factors Associated with Herpes Simplex Virus Type 2 Infection in Patients Attending a Baltimore City Emergency Department

Objectives

Herpes simplex virus type 2 (HSV-2) is a common sexually transmitted disease, but there is limited data on its epidemiology among urban populations. The urban Emergency Department (ED) is a potential venue for surveillance as it predominantly serves an inner city minority population. We evaluate the seroprevalence and factors associated with HSV-2 infection among patients attending the Johns Hopkins Hospital Adult Emergency Department (JHH ED).

Methods

An identity unlinked-serosurvey was conducted between 6/2007 and 9/2007 in the JHH ED; sera were tested by the Focus HerpeSelect ELISA. Prevalence risk ratios (PRR) were used to determine factors associated with HSV-2 infection.

Results

Of 3,408 serum samples, 1,853 (54.4%) were seropositive for HSV-2. Females (adjPRR  = 1.47, 95% CI 1.38–1.56), non-Hispanic blacks (adjPRR  = 2.03, 95% CI 1.82–2.27), single (adjPRR  = 1.15, 95% CI 1.07–1.25), divorced (adjPRR  = 1.28, 95% CI 1.15–1.41), and unemployed patients (adjPRR  = 1.13, 95% CI 1.05–1.21) had significantly higher rates of HSV-2 infection. Though certain zip codes had significantly higher seroprevalence of HSV-2, this effect was completely attenuated when controlling for age and gender.

Conclusions

Seroprevalence of HSV-2 in the JHH ED was higher than U.S. national estimates; however, factors associated with HSV-2 infection were similar. The high seroprevalence of HSV-2 in this urban ED highlights the need for targeted testing and treatment. Cross-sectional serosurveys in the urban ED may help to examine the epidemiology of HSV-2.     

Magnesium Sulfate in Emergency Department Patients with Hypertension

To compare the effect of IV magnesium with other antihypertensives in emergency department (ED) patients with hypertension. ED patients with a systolic BP > 135 mmHg or diastolic BP > 85 were approached for entry into the study. Those granting consent were randomly placed into one of three treatment groups: (1) 1.5 gm IV MgSO₄ (n = 42), (2) a parenteral or oral antihypertensive agent (n = 41), (3) both IV MgSO₄ and an antihypertensive agent (n = 44). Systolic and diastolic blood pressures were measured at entry into the study and at 15, 30, 45, and 60 min after magnesium or other antihypertensive medications were given. The main outcome measure was blood pressure at 60 min, and results were compared using one-way analysis of variance with the post hoc Tukey HSD test. Compared to systolic and diastolic blood pressures at time 0, both were lower at 15, 30, 45, and 60 min in all groups (p < 0.05). No significant difference in systolic or diastolic BP at any time point was observed when response to treatment was compared between the three groups. Intravenous MgSO₄ is as effective as antihypertensives at lowering BP in emergency department patients.     

Association between Birth Order and Emergency Room Visits and Acute Hospital Admissions following Pediatric Vaccination: A Self-Controlled Study

Objective

We investigated the association between a child''s birth order and emergency room (ER) visits and hospital admissions following 2-,4-,6- and 12-month pediatric vaccinations.

Methods

We included all children born in Ontario between April 1^st, 2006 and March 31^st, 2009 who received a qualifying vaccination. We identified vaccinations, ER visits and admissions using health administrative data housed at the Institute for Clinical Evaluative Sciences. We used the self-controlled case series design to compare the relative incidence (RI) of events among 1^st-born and later-born children using relative incidence ratios (RIR).

Results

For the 2-month vaccination, the RIR for 1^st-borns versus later-born children was 1.37 (95% CI: 1.19–1.57), which translates to 112 additional events/100,000 vaccinated. For the 4-month vaccination, the RIR for 1^st-borns vs. later-borns was 1.70 (95% CI: 1.45–1.99), representing 157 additional events/100,000 vaccinated. At 6 months, the RIR for 1^st vs. later-borns was 1.27 (95% CI: 1.09–1.48), or 77 excess events/100,000 vaccinated. At the 12-month vaccination, the RIR was 1.11 (95% CI: 1.02–1.21), or 249 excess events/100,000 vaccinated.

Conclusions

Birth order is associated with increased incidence of ER visits and hospitalizations following vaccination in infancy. 1^st-born children had significantly higher relative incidence of events compared to later-born children.     

Sequence Variations in Human Immunodeficiency Virus Type 1 Nef Are Associated with Different Stages of Disease

nef alleles derived from a large number of individuals infected with human immunodeficiency virus type 1 (HIV-1) were analyzed to investigate the frequency of disrupted nef genes and to elucidate whether specific amino acid substitutions in Nef are associated with different stages of disease. We confirm that deletions or gross abnormalities in nef are rarely present. However, a comparison of Nef consensus sequences derived from 41 long-term nonprogressors and from 50 individuals with progressive HIV-1 infection revealed that specific variations are associated with different stages of infection. Five amino acid variations in Nef (T15, N51, H102, L170, and E182) were more frequently observed among nonprogressors, while nine features (an additional N-terminal PxxP motif, A15, R39, T51, T157, C163, N169, Q170, and M182) were more frequently found in progressors. Strong correlations between the frequency of these variations in Nef and both the CD4(+)-cell count and the viral load were observed. Moreover, analysis of sequential samples obtained from two progressors revealed that several variations in Nef, which were more commonly observed in patients with low CD4(+)-T-cell counts, were detected only during or after progression to immunodeficiency. Our results indicate that sequence variations in Nef are associated with different stages of HIV-1 infection and suggest a link between nef gene function and the immune status of the infected individual.