Education Outcomes of Children Born Late Preterm: A Retrospective Whole-Population Cohort Study

BACKGROUND

Early life exposures can have an impact on a child's developmental trajectory and children born late preterm (34-36 weeks gestational age) are increasingly recognized to have health and developmental setbacks that extend into childhood.

OBJECTIVES

The purpose of this study was to assess whether late preterm birth was associated with poorer developmental and educational outcomes in the early childhood period, after controlling for health and social factors.

METHODS

We conducted a retrospective cohort study using administrative databases housed at the Manitoba Centre for Health Policy, including all children born late preterm (34-36 weeks gestational age (GA)) and at full-term (39-41 weeks GA) between 2000 and 2005 in urban Manitoba (N = 28,100). Logistic regression was used to examine the association between gestational age (GA) and outcomes, after adjusting for covariates.

RESULTS

Adjusted analyses demonstrated that children born late preterm had a higher prevalence of attention deficit hyperactivity disorder (ADHD) (aOR = 1.25, 95% CI [1.03, 1.51]), were more likely to be vulnerable in the language and cognitive (aOR = 1.29, 95% CI [1.06, 1.57]), communication and general knowledge (aOR = 1.24, 95% CI [1.01, 1.53]), and physical health and well-being (aOR = 1.27, 95% CI [1.04, 1.53]) domains of development at kindergarten, and were more likely to repeat kindergarten or grade 1 (aOR = 1.52, 95% CI [1.03, 2.25]) compared to children born at term. They did not differ in receipt of special education funding, in social maturity or emotional development at kindergarten, and in reading and numeracy assessments in the third grade.

CONCLUSIONS

Given that the late preterm population makes up 75% of the preterm population, their poorer outcomes have implications at the population level. This study underscores the importance of recognizing the developmental vulnerability of this population and adequately accounting for the social differences between children born late preterm and at term.

Prevalence and clinical, social, and health care predictors of miscarriage

BACKGROUND

Pregnancy loss is common and several factors (e.g. chromosomal anomalies, parental age) are known to increase the risk of occurrence. However, much existing research focuses on recurrent loss; comparatively little is known about the predictors of a first miscarriage. Our objective was to estimate the population-level prevalence of miscarriages and to assess the contributions of clinical, social, and health care use factors as predictors of the first detected occurrence of these losses.

METHODS

In this population-based cohort study, we used linked administrative health data to estimate annual rates of miscarriage in the Manitoba population from 2003 to 2014, as a share of identified pregnancies. We compared the unadjusted associations between clinical, social, and health care use factors and first detected miscarriage compared with a live birth. We estimated multivariable generalized linear models to assess whether risk factors were associated with first detected miscarriage controlling for other predictors.

RESULTS

We estimated an average annual miscarriage rate of 11.3%. In our final sample (n = 79,978 women), the fully-adjusted model indicated that use of infertility drugs was associated with a 4 percentage point higher risk of miscarriage (95% CI 0.02, 0.06) and a past suicide attempt with a 3 percentage point higher risk (95% CI -0.002, 0.07). Women with high morbidity were twice as likely to experience a miscarriage compared to women with low morbidity (RD = 0.12, 95% CI 0.09, 0.15). Women on income assistance had a 3 percentage point lower risk (95% CI -0.04, -0.02).

CONCLUSIONS

We estimate that 1 in 9 pregnant women in Manitoba experience and seek care for a miscarriage. After adjusting for clinical factors, past health care use and morbidity contribute important additional information about the risk of first detected miscarriage. Social factors may also be informative.

Maternal Distress During Pregnancy and Recurrence in Early Childhood Predicts Atopic Dermatitis and Asthma in Childhood

BACKGROUND

Early-life stress is becoming an important determinant of immune system programming. Maternal prenatal distress is found to be associated with atopic disease in offspring but the separate effects of postnatal distress are not well-studied.

RESEARCH QUESTION

Does the likelihood of asthma and atopic dermatitis in children increase when they are exposed to maternal distress pre- and postnatally in a sex-specific manner?

STUDY DESIGN AND METHODS

Using data from a provincial newborn screen and health-care database for 12,587 children born in 2004, maternal distress (depression or anxiety) was defined as prenatal, self-limiting, recurrent, or late-onset postpartum. Atopic dermatitis (AD) and asthma at ages 5 years and 7 years of age were diagnosed by using hospitalization, physician visit, or prescription records. Associations between maternal distress and childhood asthma and AD were determined by using multiple logistic regression.

RESULTS

After adjusting for risk factors, a significant association between maternal prenatal (OR, 1.27; 95% CI, 1.11-1.46), recurrent postpartum (OR, 1.28; 95% CI, 1.11-1.48), and late-onset postpartum (OR, 1.19, 95% CI, 1.06-1.34) distress was found with AD at age 5 years. Asthma at age 7 years was also associated with maternal prenatal distress (OR, 1.57; 95% CI, 1.29-1.91) and late-onset postnatal distress (OR, 1.22; 95% CI, 1.01-1.46). Self-limiting postnatal distress was not found to be a risk factor for either atopic condition. Associations with AD or asthma were of a similar magnitude in boys and girls; the exception was recurrent postnatal distress, which increased risk for asthma in boys only.

INTERPRETATION

This population-based study provides evidence for sex-specific associations between maternal prenatal and postnatal distress, as well as the development of AD and asthma. The findings support recommendations for greater psychosocial support of mothers during pregnancy and early childhood to prevent childhood atopic disease.

The Association of Inadequate and Intensive Prenatal Care With Maternal, Fetal, and Infant Outcomes: A Population-Based Study in Manitoba, Canada

OBJECTIVE

Little is known about how prenatal care influences health outcomes in Canada. The objective of this study was to examine the association of prenatal care utilization with maternal, fetal, and infant outcomes in Manitoba.

METHODS

This retrospective cohort study conducted at the Manitoba Centre for Health Policy investigated all deliveries of singleton births from 2004-2005 to 2008-2009 (N = 67 076). The proportion of women receiving inadequate, intermediate/adequate, and intensive prenatal care was calculated. Multivariable logistic regression was used to examine the association of inadequate and intensive prenatal care with maternal and fetal-infant health outcomes, health care use, and maternal health-related behaviours.

RESULTS

The distribution of prenatal care utilization was 11.6% inadequate, 84.4% intermediate/adequate, and 4.0% intensive. After adjusting for sociodemographic factors and maternal health conditions, inadequate prenatal care was associated with increased odds of stillbirth, preterm birth, low birth weight, small for gestational age (SGA), admission to the NICU, postpartum depressive/anxiety disorders, and short interpregnancy interval to next birth. Women with inadequate prenatal care had reduced odds of initiating breastfeeding or having their infant immunized. Intensive prenatal care was associated with reduced odds of stillbirth, preterm birth, and low birth weight and increased odds of postpartum depressive/anxiety disorders, initiation of breastfeeding, and infant immunization.

CONCLUSION

Inadequate prenatal care was associated with increased odds of several adverse pregnancy outcomes and lower likelihood of health-related behaviours, whereas intensive prenatal care was associated with reduced odds of some adverse pregnancy outcomes and higher likelihood of health-related behaviours. Ensuring women receive adequate prenatal care may improve pregnancy outcomes.

Inequities in utilization of prenatal care: a population-based study in the Canadian province of Manitoba

BACKGROUND

Ensuring high quality and equitable maternity services is important to promote positive pregnancy outcomes. Despite a universal health care system, previous research shows neighborhood-level inequities in utilization of prenatal care in Manitoba, Canada. The purpose of this population-based retrospective cohort study was to describe prenatal care utilization among women giving birth in Manitoba, and to determine individual-level factors associated with inadequate prenatal care.

METHODS

We studied women giving birth in Manitoba from 2004/05-2008/09 using data from a repository of de-identified administrative databases at the Manitoba Centre for Health Policy. The proportion of women receiving inadequate prenatal care was calculated using a utilization index. Multivariable logistic regressions were used to identify factors associated with inadequate prenatal care for the population, and for a subset with more detailed risk information.

RESULTS

Overall, 11.5% of women in Manitoba received inadequate, 51.0% intermediate, 33.3% adequate, and 4.1% intensive prenatal care (N = 68,132). Factors associated with inadequate prenatal care in the population-based model (N = 64,166) included northern or rural residence, young maternal age (at current and first birth), lone parent, parity 4 or more, short inter-pregnancy interval, receiving income assistance, and living in a low-income neighborhood. Medical conditions such as multiple birth, hypertensive disorders, antepartum hemorrhage, diabetes, and prenatal psychological distress were associated with lower odds of inadequate prenatal care. In the subset model (N = 55,048), the previous factors remained significant, with additional factors being maternal education less than high school, social isolation, and prenatal smoking, alcohol, and/or illicit drug use.

CONCLUSION

The rate of inadequate prenatal care in Manitoba ranged from 10.5-12.5%, and increased significantly over the study period. Factors associated with inadequate prenatal care included geographic, demographic, socioeconomic, and pregnancy-related factors. Rates of inadequate prenatal care varied across geographic regions, indicating persistent inequities in use of prenatal care. Inadequate prenatal care was associated with several individual indicators of social disadvantage, such as low income, education less than high school, and social isolation. These findings can inform policy makers and program planners about regions and populations most at-risk for inadequate prenatal care and assist with development of initiatives to reduce inequities in utilization of prenatal care.

Interpregnancy Intervals in a Contemporary Manitoba Cohort: Prevalence of So-Called Suboptimal Intervals and Associated Maternal Characteristics

OBJECTIVE

Short and long interpregnancy intervals (IPIs) have been associated with various adverse outcomes, and a 2016 American College of Obstetricians and Gynecologists' Committee Opinion recommends an optimal IPI of 18 months to 5 years. Descriptive data on the IPI in Canada are lacking. The objective of this study was to examine IPIs in a Manitoba cohort.

METHODS

The study analyzed a subset of records from a larger dataset used to examine the IPI and adverse perinatal outcomes. For that study, Manitoba's Hospital Abstracts data were searched to identify births from 1985 to 2014. Each two consecutive live births to the same mother formed a sibling pair. The IPI was calculated as the interval between the two siblings' births, minus the younger sibling's GA. Information on maternal characteristics was extracted from various datasets housed in the Manitoba Population Research Data Repository. The current analysis examined second and higher-order births between 2010 and 2014. The proportion of suboptimal IPIs was determined and IPIs were cross-tabulated with birth year and maternal subgroups.

RESULTS

More than half of pregnancies were conceived following a suboptimal interval. IPIs of less than 6 months - which have been associated with the highest risk of adverse outcomes - were more prevalent among certain subgroups. These included younger women as well as women who received inadequate prenatal care, smoked or drank alcohol during pregnancy, were low income, or did not graduate from high school.

CONCLUSION

Suboptimal IPIs were common in this Manitoba cohort. Stakeholders should consider whether greater efforts to promote appropriate birth spacing are warranted.

Examining Early Childhood Health Outcomes of Children Born Late Preterm in Urban Manitoba

Objective The late preterm population [34-36 weeks gestational age (GA)] is known to incur increased morbidity in the infancy stage compared to the population born at term (39-41 weeks GA). This study aimed to examine the health of these children during their early childhood years, with specific attention to the role of socioeconomic status. Methods A retrospective cohort study was conducted using data from the Manitoba Centre for Health Policy, including all live-born children born at 34-36 and 39-41 weeks GA in urban Manitoba between 2000 and 2005 (n = 28,100). Multivariable logistic regression was used to examine the association of GA with early childhood morbidity after controlling for maternal, child and family level variables. Results The late preterm population was found to have significantly greater adjusted odds of lower respiratory tract infections in the preschool years (aOR = 1.59 [1.24, 2.04]) and asthma at school age (aOR = 1.33 [1.18, 1.47]) compared to the population born at term. The groups also differed in health care utilization at ages 4 (aOR = 1.19 [1.06,1.34]) and 7 years (aOR = 1.24 [1.09, 1.42]). Additional variables associated with poor outcomes suggest that social deprivation and GA simultaneously have a negative impact on early childhood development. Conclusions for Practice Adjustment for predictors of poor early childhood development, including socioeconomic status, were found to attenuate but not eliminate health differences between children born late preterm and children born at term. Poorer health outcomes that extend into childhood have implications for practice at the population level and suggest a need for further follow-up post discharge.

Association between home visiting interventions and First Nations families' health and social outcomes in Manitoba, Canada: protocol for a study of linked population-based administrative data

INTRODUCTION

First Nations people are descendants of Canada's original inhabitants. In consequence of historical and ongoing structural injustices, many First Nations families struggle with challenging living conditions, including high rates of poverty, poor housing conditions, mental illness and social isolation. These risk factors impede caregivers' abilities to meet their children's basic physical and psychosocial needs. Home visiting programmes were developed to support child developmental health in families facing parenting challenges. However, whether home visiting is an effective intervention for First Nations families has not been examined. We are evaluating two home visiting programmes in Manitoba, Canada, to determine whether they promote nurturing family environments for First Nations children.

METHODS AND ANALYSIS

This research builds on new and established relationships among academic researchers, government decision-makers and First Nations stakeholders. We will link health, education and social services data from the Manitoba Population Research Data Repository to data from two home visiting programmes in Manitoba. Logistic regression modelling will be used to assess whether programme participation is associated with improved child developmental health, better connections between families and social services, reduced instances of child maltreatment and being taken into out-of-home care by child welfare and reduced inequities for First Nations families. Non-participating individuals with similar sociodemographic characteristics will serve as comparators. We will use an interrupted time series approach to test for differences in outcomes before and after programme implementation and a propensity score analysis to compare differences between participants and non-participants.

ETHICS AND DISSEMINATION

Approvals were granted by the Health Information Research Governance Committee of the First Nations Health and Social Secretariat of Manitoba and the University of Manitoba Health Research Ethics Board. Our integrated knowledge translation approach will involve disseminating findings through government and community briefings, developing lay summaries and infographics, presenting at academic conferences and publishing in scientific journals.

Interpregnancy Interval and Congenital Anomalies: A Record-Linkage Study Using the Manitoba Population Research Data Repository

OBJECTIVE

Congenital anomalies are a serious public health issue, and relatively few modifiable risk factors have been identified. Our objective was to investigate one such potential risk factor, the interpregnancy interval (IPI).

METHODS

We conducted a secondary analysis of data housed at the Manitoba Centre for Health Policy. In-hospital live births and stillbirths of at least 20 weeks' gestation were identified, and consecutive births to the same mother were grouped into sibling pairs to calculate the IPI for the younger siblings of each pair. Logistic regression models were fit to examine the association between the IPI and any congenital anomaly, as well as CNS and chromosomal anomalies, while controlling for potentially confounding sociodemographic and clinical factors.

RESULTS

Among 172 909 live births and stillbirths, the IPI was not significantly associated with congenital anomalies overall or with chromosomal anomalies. Short IPIs were associated with significantly increased odds of CNS anomalies relative to IPIs of 18-23 months (adjusted OR [aOR] for IPIs <6 months 2.15; 95% CI 1.48-3.12), whereas the aOR for IPIs ≥60 months was elevated but not statistically significant (aOR 1.50; 95% CI 0.96-2.34). In a sensitivity analysis in which the cohort was restricted to births from 2003 onwards (which yielded more complete data on health-related behaviours), the observed effect for IPIs shorter than 6 months and CNS anomalies was attenuated and no longer significant, but it remained elevated (aOR 1.65; 95% CI 0.85-3.24).

CONCLUSION

The findings for CNS anomalies warrant further investigation.

Is the Families First Home Visiting Program Effective in Reducing Child Maltreatment and Improving Child Development?

While home visiting programs are among the most widespread interventions to support at-risk families, there is a paucity of research investigating these programs under real-world conditions. The effectiveness of Families First home visiting (FFHV) was examined for decreasing rates of being in care of child welfare, decreasing hospitalizations for maltreatment-related injuries, and improving child development at school entry. Data for 4,562 children from home visiting and 5,184 comparison children were linked to deidentified administrative health, social services, and education data. FFHV was associated with lower rates of being in care by child's first, second, and third birthday (adjusted risk ratio [aRR] = 0.75, 0.79, and 0.81, respectively) and lower rates of hospitalization for maltreatment-related injuries by third birthday (aRR = 0.59). No differences were found in child development at kindergarten. FFHV should be offered to at-risk families to decrease child maltreatment. Program enhancements are required to improve child development at school entry.

Interpregnancy Interval and Adverse Perinatal Outcomes: A Record-Linkage Study Using the Manitoba Population Research Data Repository

OBJECTIVE

To examine the association between the interpregnancy interval (IPI) and preterm birth, low birth weight, and SGA birth in a developed country with universal health coverage.

METHODS

We conducted a secondary analysis of data housed at the Manitoba Centre for Health Policy. All live births in Manitoba hospitals over a 29-year period were identified and consecutive births to the same mother were grouped into sibling pairs to calculate the IPI for the younger siblings. Logistic regression models were fit to examine the association between the IPI and adverse perinatal outcomes, adjusted for potentially confounding sociodemographic and clinical factors.

RESULTS

In a cohort of more than 171 000 births and relative to IPIs of 18 to 23 months, IPIs shorter than 12 and longer than 23 months were associated with significantly increased odds of preterm birth overall and both medically indicated and spontaneous preterm births, low birth weight, and SGA birth. The strongest association observed was for intervals shorter than 6 months and spontaneous preterm birth (adjusted OR 1.83, 95% CI 1.65-2.03). When the outcome was modelled as GA categories, the strongest association observed was for intervals shorter than 6 months and early preterm birth (<34 weeks' GA; adjusted OR 2.47, 95% CI 2.07-2.94).

CONCLUSION

If the associations observed between the IPI and adverse perinatal outcomes in this large, population-based cohort are causal, birth spacing could form an important target of public health messaging in Canada.

Unconditional Prenatal Income Supplement and Birth Outcomes

BACKGROUND AND OBJECTIVES

Perinatal outcomes have improved in developed countries but remain poor for disadvantaged populations. We examined whether an unconditional income supplement to low-income pregnant women was associated with improved birth outcomes.

METHODS

This study included all mother-newborn pairs (2003-2010) in Manitoba, Canada, where the mother received prenatal social assistance, the infant was born in the hospital, and the pair had a risk screen (N = 14 591). Low-income women who received the income supplement (Healthy Baby Prenatal Benefit [HBPB], n = 10 738) were compared with low-income women who did not receive HBPB (n = 3853) on the following factors: low birth weight, preterm, small and large for gestational age, Apgar score, breastfeeding initiation, neonatal readmission, and newborn hospital length of stay (LOS). Covariates from risk screens were used to develop propensity scores and to balance differences between groups in regression models; γ sensitivity analyses were conducted to assess sensitivity to unmeasured confounding. Population-attributable and preventable fractions were calculated.

RESULTS

HBPB was associated with reductions in low birth weight (aRR, 0.71 [95% CI, 0.63-0.81]), preterm births (aRR, 0.76 [95% CI, 0.69-0.84]) and small for gestational age births (aRR, 0.90 [95% CI, 0.81-0.99]) and increases in breastfeeding (aRR, 1.06 [95% CI, 1.03-1.09]) and large for gestational age births (aRR, 1.13 [95% CI, 1.05-1.23]). For vaginal births, HBPB was associated with shortened LOS (weighted mean, 2.86; P < .0001). Results for breastfeeding, low birth weight, preterm birth, and LOS were robust to unmeasured confounding. Reductions of 21% (95% CI, 13.6-28.3) for low birth weight births and 17.5% (95% CI, 11.2-23.8) for preterm births were associated with HBPB.

CONCLUSIONS

Receipt of an unconditional prenatal income supplement was associated with positive outcomes. Placing conditions on income supplements may not be necessary to promote prenatal and perinatal health.

Data resource profile: Pathways to Health and Social Equity for Children (PATHS Equity for Children)

The PATHS Data Resource is a unique database comprising data that follow individuals from the prenatal period to adulthood. The PATHS Resource was developed for conducting longitudinal epidemiological research into child health and health equity. It contains individual-level data on health, socioeconomic status, social services and education. Individuals' data are linkable across these domains, allowing researchers to follow children through childhood and across a variety of sectors. PATHS includes nearly all individuals that were born between 1984 and 2012 and registered with Manitoba's universal health insurance programme at some point during childhood. All PATHS data are anonymized. Key concepts, definitions and algorithms necessary to work with the PATHS Resource are freely accessible online and an interactive forum is available to new researchers working with these data. The PATHS Resource is one of the richest and most complete databases assembled for conducting longitudinal epidemiological research, incorporating many variables that address the social determinants of health and health equity. Interested researchers are encouraged to contact [mchp_access@cpe.umanitoba.ca] to obtain access to PATHS to use in their own programmes of research.

The effect of neighborhood socioeconomic status on education and health outcomes for children living in social housing

OBJECTIVES

We explored differences in health and education outcomes between children living in social housing and not, and effects of social housing's neighborhood socioeconomic status.

METHODS

In this cohort study, we used the population-based repository of administrative data at the Manitoba Centre for Health Policy. We included children aged 0 to 19 years in Winnipeg, Manitoba, in fiscal years 2006-2007 to 2008-2009 (n = 13,238 social housing; n = 174,017 others). We examined 5 outcomes: age-2 complete immunization, a school-readiness measure, adolescent pregnancy (ages 15-19 years), grade-9 completion, and high-school completion. Logistic regression and generalized estimating equation modeling generated rates. We derived neighborhood income quintiles (Q1 lowest, Q5 highest) from average household income census data.

RESULTS

Children in social housing fared worse than comparative children within each neighborhood income quintile. When we compared children in social housing by quintile, preschool indicators (immunization and school readiness) were similar, but adolescent outcomes (grade-9 and high-school completion, adolescent pregnancy) were better in Q3 to Q5.

CONCLUSIONS

Children in social housing had poorer health and education outcomes than all others, but living in social housing in wealthier areas was associated with better adolescent outcomes.

Have we left some behind? Trends in socio-economic inequalities in breastfeeding initiation: a population-based epidemiological surveillance study

OBJECTIVES

Breastfeeding is associated with improved health. Surveillance data show that breastfeeding initiation rates have increased; however, limited work has examined trends in socio-economic inequalities in initiation. The study's research question was whether socio-economic inequalities in breastfeeding initiation have changed over the past 20 years.

METHODS

This population-based study is a project within PATHS Equity for Children. Analyses used hospital discharge data for Manitoba mother-infant dyads with live births, 1988-2011 (n=316,027). Income quintiles were created, each with ~20% of dyads. Three-year, overall and by-quintile breastfeeding initiation rates were estimated for Manitoba and two hospitals. Age-adjusted rates were estimated for Manitoba. Rates were modelled using generalized linear models. Three measures, rate ratios (RRs), rate differences (RDs) and concentration indices, assessed inequality at each time point. We also compared concentration indices with Gini coefficients to assess breastfeeding inequality vis-à-vis income inequality. Trend analyses tested for changes over time.

RESULTS

Manitoba and Hospital A initiation rates increased; Hospital B rates did not change. Significant inequalities existed in nearly every period, across all three measures: RRs, RDs and concentration indices. RRs and concentration indices suggested little to no change in inequality from 1988 to 2011. RDs for Manitoba (comparing initiation in the highest to lowest income quintiles) did not change significantly over time. RDs decreased for Hospital A, suggesting decreasing socio-economic inequalities in breastfeeding; RDs increased for Hospital B. Income inequality increased significantly in Manitoba during the study period.

CONCLUSIONS

Overall breastfeeding initiation rates can improve while inequality persists or worsens.

Earlier onset of complications in youth with type 2 diabetes

OBJECTIVE

To evaluate the risk of complications in youth with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Population-based cohorts of 342 youth (1-18 years of age) with prevalent type 2 diabetes, 1,011 youth with type 1 diabetes, and 1,710 nondiabetic control youth were identified between 1986 and 2007 from a clinical registry and linked to health care records to assess long-term outcomes using ICD-9CM and ICD-10CA codes.

RESULTS

Youth with type 2 diabetes had an increased risk of any complication (hazard ratio 1.47 [95% CI 1.02-2.12]). Significant adverse clinical factors included age at diagnosis (1.08 [1.02-2.12]), HbA1c (1.06 [1.01-1.12]), and, surprisingly, renin-angiotensin-aldosterone system (RAAS) inhibitor use (1.75 [1.27-2.41]). HNF-1α G319S polymorphism was protective in the type 2 diabetes cohort (0.58 [0.34-0.99]). Kaplan-Meier statistics revealed an earlier diagnosis of renal and neurologic complications in the type 2 diabetes cohort, manifesting within 5 years of diagnosis. No difference in retinopathy was seen. Cardiovascular and cerebrovascular diseases were rare; however, major complications (dialysis, blindness, or amputation) started to manifest 10 years after diagnosis in the type 2 diabetes cohort. Youth with type 2 diabetes had higher rates of all outcomes than nondiabetic control youth and an overall 6.15-fold increased risk of any vascular disease.

CONCLUSIONS

Youth with type 2 diabetes exhibit complications sooner than youth with type 1 diabetes. Younger age at diagnosis is potentially protective, and glycemic control is an important modifiable risk factor. The unexpected adverse association between RAAS inhibitor use and outcome is likely a confounder by indication; however, further evaluation in young people is warranted.

Trends in pediatric dental surgery for severe early childhood caries in Manitoba, Canada

INTRODUCTION

Caries is the most common chronic disease of childhood, and severe forms may necessitate rehabilitative dental surgery. In this study, administrative data related to pediatric dental surgery performed under general anesthesia to treat severe early childhood caries in Manitoba, Canada, were reviewed to determine trends in pediatric dental surgery, as well as geographic, regional and socio-economic variations in surgical rates.

METHODS

The total number of dental surgery cases performed under general anesthesia was obtained from provincial administrative databases for fiscal years from 1997-98 to 2006-07. Codes from the International Classification of Diseases and Related Health Problems (9th or 10th revision, as appropriate) were used to identify children who underwent extractions under general anesthesia for a slightly earlier fiscal year period (1996-97 to 2005-06). Each 10-year period was divided into two 5-year periods for comparisons over time. Analyses included descriptive and bivariate statistics, with the data being disaggregated by regional health authority (RHA) or by community area (for Winnipeg). Comparisons for which p ≤ 0.05 were defined as statistically significant.

RESULTS

A total of 18,544 children had dental surgery under general anesthesia between 1997-98 and 2006-07 (mean age ± standard deviation 3.28 ± 1.02 years). Many of the children requiring surgery resided in one northern RHA (26.8%) or the Winnipeg RHA (23.8%). More than half of the RHAs (7/11) displayed significant increases in the rate of surgery, with northern RHAs having the highest rates. Within Winnipeg, 3 of the 12 community areas had significant increases in the rate of surgery. Two inner-city neighborhoods accounted for nearly 50% of surgical cases. The rate of extractions under general anesthesia increased significantly in 6 of the 11 RHAs, with northern RHAs having the highest rates. Four Winnipeg communities experienced significant increases in the extraction rate over time.

CONCLUSION

Pediatric dental surgery under general anesthesia for treatment of severe early childhood caries is common in Manitoba, and the demand increased in several communities over the study period. These results are being shared with decision-makers and communities to identify regions where oral health promotion is needed.

Use of health, education, and social services by individuals with fetal alcohol spectrum disorder

BACKGROUND

Fetal Alcohol Spectrum Disorder (FASD) is the leading cause of intellectual disability in western society, presenting a significant burden on health, education and social services. Quantifying the burden of FASD is important for service planning and policy and program development.

OBJECTIVE

To describe the health, education and social service use of individuals with FASD to provide an indication of the burden of service use of the disorder.

METHODS

Using a matched-cohort design health, education and social service data were linked with clinical records on individuals 6+ years diagnosed with FASD between 1999/2000-2009/10 (N=717). Matching was 2:1 with a general population (gPop) and asthma group by age, sex and area-level income. Adjusted rates and relative risks were calculated using Generalized Linear Models.

RESULTS

Hospitalizations were higher in the FASD compared to gPop (adjusted relative risk=3.44 (95% confidence interval=2.29, 5.17)) and asthma (2.87 (1.94, 4.25)) groups, whereas for physician visits and overall prescriptions, the FASD group differed from only the gPop group (1.58 (1.34, 1.84); 1.44 (1.22, 1.72), respectively). Antibiotics, pain killers and anti-psychotics were similar across groups whereas antidepressants and psychostimulants were higher in the FASD group (antidepressants: FASD vs. gPop 8.76 (2.82, 27.21); FASD vs. asthma 2.10 (1.15, 3.83); psychostimulants: FASD vs. gPop 5.78 (2.89, 11.57); FASD vs. asthma 2.47 (1.37, 4.47)). Attention-deficit\hyperactivity disorder was higher in the FASD than the gPop and asthma groups (6.41 (3.29, 12.49); 3.12 (1.97, 4.93), respectively). Education and social service use was higher for the FASD than either of the other groups for all measures (FASD vs. gPop and FASD vs. asthma, respectively for: grade repetition 3.06 (1.58, 5.94); 3.48 (1.79, 6.78); receipt of any special education funding 9.22 (6.23, 13.64); 6.10 (4.14, 8.99); family receipt of income assistance 1.74 (1.33, 2.27); 1.89 (1.45, 2.47); child in care 13.19 (5.84, 29.78);10.70 (4.80, 23.88); and receipt of child welfare services 5.70 (4.21, 7.71); 4.94 (3.67, 6.66)).

CONCLUSION

The health, education and social service utilization burden of individuals with FASD is substantial, greater than that of individuals in the general population and with chronic illness (i.e., asthma). The findings highlight the need for multisystem supports for those with FASD, and comprehensive prevention programs.

Administrative data linkage as a tool for child maltreatment research

Linking administrative data records for the same individuals across services and over time offers a powerful, population-wide resource for child maltreatment research that can be used to identify risk and protective factors and to examine outcomes. Multistage de-identification processes have been developed to protect privacy and maintain confidentiality of the datasets. Lack of information on those not coming to the attention of child protection agencies, and limited information on certain variables, such as individual-level SES and parenting practices, is outweighed by strengths that include large and unbiased samples, objective measures, comprehensive long-term follow-up, continuous data collection, and relatively low expense. Ever emerging methodologies and expanded holdings ensure that research using linked population-wide databases will make important contributions to the study of child maltreatment.

High burden of kidney disease in youth-onset type 2 diabetes

OBJECTIVE

To evaluate renal outcomes and survival in youth with type 2 diabetes (T2DM) versus type 1 diabetes (T1DM) versus nondiabetic control subjects.

RESEARCH DESIGN AND METHODS

In total, 342 prevalent youth (aged 1-18 years) with T2DM, 1,011 youth with T1DM, and 1,710 control subjects identified from 1986 to 2007 were anonymously linked to health care records housed at the Manitoba Centre for Health Policy to assess long-term outcomes using ICD codes.

RESULTS

Youth with T2DM were found to have a fourfold increased risk of renal failure versus youth with T1DM. Risk factors associated with renal failure were renin angiotensin aldosterone system inhibitor use and albuminuria in adolescence. Compared with control subjects (age, sex, and postal code matched), youth with T2DM had a 23-fold increased risk of renal failure and a 39-fold increased risk of dialysis. Kaplan-Meier survival at 10 years was 91.4% in the type 2 diabetic group versus 99.5% in the type 1 diabetic group (P < 0.0001). Renal survival was 100% at 10 years in both groups. It decreased to 92.0% at 15 years and 55.0% at 20 years in the type 2 diabetic group but remained stable in the type 1 diabetic group (P < 0.0001).

CONCLUSIONS

Youth with T2DM are at high risk of adverse renal outcomes and death. Albuminuria and angiotensin aldosterone system inhibitor use, which may be a marker of severity of disease, are associated with poor outcomes in early adulthood.

Evaluation of a newborn screen for predicting out-of-home placement

A newborn screen designed to predict family risk was examined to: (a) determine whether all families with newborns were screened; (b) evaluate its predictive validity for identifying risk of out-of-home placement, as a proxy for maltreatment; (c) determine which items were most predictive of out-of-home placement. All infants born in Manitoba, Canada from 2000 to 2002 were followed until March 31, 2004 (N = 40,886) by linking four population-based data sets: (a) newborn screening data on biological, psychological, and social risks; (b) population registry data on demographics; (c) hospital discharge data on newborn birth records; (d) data on children entering out-of-home care. Of the study population, 18.4% were not screened and 3.0% were placed in out-of-home care at least once during the study period. Infants not screened were twice as likely to enter care compared to those screened (4.9% vs. 2.5%). Infants screening at risk were 15 times more likely to enter care than those screening "not at risk." Sensitivity and specificity of the screen were 77.6% and 83.3%, respectively. Screening efforts to identify vulnerable families missed a substantial portion of families needing support. The screening tool demonstrated moderate predictive validity for identifying children at risk of entering care in the first years of life.

Program for expectant and new mothers: a population-based study of participation

BACKGROUND

The Manitoba Healthy Baby Program is aimed at promoting pre- and perinatal health and includes two components: 1) prenatal income supplement; 2) community support programs. The goal of this research was to determine the uptake of these components by target groups.

METHODS

Data on participation in each of the two program components were linked to data on all hospital births in Manitoba between 2004/05 through 2007/08. Descriptive analyses of participation by maternal characteristics were produced. Logistic regression analyses were conducted to identify factors associated with participation in the two programs. Separate regressions were run for two groups of women giving birth during the study period: 1) total population; 2) those receiving provincial income assistance during the prenatal period.

RESULTS

Almost 30% of women giving birth in Manitoba received the Healthy Baby prenatal income supplement, whereas only 12.6% participated in any community support programs. Over one quarter (26.4%) of pregnant women on income assistance did not apply for and receive the prenatal income supplement, despite all being eligible for it. Furthermore, 77.8% of women on income assistance did not participate in community support programs. Factors associated with both receipt of the prenatal benefit and participation in community support programs included lower SES, receipt of income assistance, obtaining adequate prenatal care, having completed high school and having depressive symptoms. Having more previous births was associated with higher odds of receiving the prenatal benefit, but lower odds of attending community support programs. Being married was associated with lower odds of receiving the prenatal benefit but higher odds of participating in community support programs.

CONCLUSIONS

Although uptake of the Healthy Baby program in Manitoba is greater for women in groups at risk for poorer perinatal outcomes, a substantial number of women eligible for this program are not receiving it; efforts to reach these women should be enhanced.

Administrative record linkage as a tool for public health research

Linked administrative databases offer a powerful resource for studying important public health issues. Methods developed and implemented in several jurisdictions across the globe have achieved high-quality linkages for conducting health and social research without compromising confidentiality. Key data available for linkage include health services utilization, population registries, place of residence, family ties, educational outcomes, and use of social services. Linking events for large populations of individuals across disparate sources and over time permits a range of research possibilities, including the capacity to study low-prevalence exposure-disease associations, multiple outcome domains within the same cohort of individuals, service utilization and chronic disease patterns, and life course and transgenerational transmission of health. Limited information on variables such as individual-level socioeconomic status (SES) and social supports is outweighed by strengths that include comprehensive follow-up, continuous data collection, objective measures, and relatively low expense. Ever advancing methodologies and data holdings guarantee that research using linked administrative databases will make increasingly important contributions to public health research.

Validation of a pediatric diabetes case definition using administrative health data in manitoba, Canada

OBJECTIVE

To validate a case definition for diabetes in the pediatric age-group using administrative health data.

RESEARCH DESIGN AND METHODS

Population-based administrative data from Manitoba, Canada for the years 2004-2006 were anonymously linked to a clinical registry to evaluate the validity of algorithms based on a combination of hospital claim, outpatient physician visit, and drug use data over 1-3 years in youth 1-18 years of age. Agreement between data sources, sensitivity, specificity, negative (NPV) and positive predictive value (PPV) were evaluated for each algorithm. In addition, ascertainment rate of each data source, prevalence, and differences between subtypes of diabetes were evaluated.

RESULTS

Agreement between data sources was very good. The diabetes definition including one or more hospitalizations or two or more outpatient claims over 2 years provided a sensitivity of 94.2%, specificity of 99.9%, PPV of 81.6% and NPV of 99.9%. The addition of one or more prescription claims to the same definition over 1 year provided similar results. Case ascertainment rates of both sources were very good to excellent and the ascertainment-corrected prevalence for youth-onset diabetes for the year 2006 was 2.4 per 1,000. It was not possible to distinguish between subtypes of diabetes within the administrative database; however, this limitation could be overcome with an anonymous linkage to the clinical registry.

CONCLUSIONS

Administrative data are a valid source for the determination of pediatric diabetes prevalence that can provide important information for health care planning and evaluation.

Administrative record linkage as a tool for public health research

Linked administrative databases offer a powerful resource for studying important public health issues. Methods developed and implemented in several jurisdictions across the globe have achieved high-quality linkages for conducting health and social research without compromising confidentiality. Key data available for linkage include health services utilization, population registries, place of residence, family ties, educational outcomes, and use of social services. Linking events for large populations of individuals across disparate sources and over time permits a range of research possibilities, including the capacity to study low-prevalence exposure-disease associations, multiple outcome domains within the same cohort of individuals, service utilization and chronic disease patterns, and life course and transgenerational transmission of health. Limited information on variables such as individual-level socioeconomic status (SES) and social supports is outweighed by strengths that include comprehensive follow-up, continuous data collection, objective measures, and relatively low expense. Ever advancing methodologies and data holdings guarantee that research using linked administrative databases will make increasingly important contributions to public health research.

Socio-economic inequities in children's injury rates: has the gradient changed over time?

INTRODUCTION

Changing socio-economic gradients in adult health over time have been documented, but little research has investigated temporal changes in child health gradients. Childhood hospitalizations for injury have fallen over the last two decades; whether the socio-economic gradient in childhood injury has changed is unknown.

METHODS

Population-based hospital discharge data were used to calculate rates of hospitalization for injury from 1986/87 through 2005/06 for all children under 20 years of age in Manitoba (average yearly number of hospitalizations = 326,357). Information on socio-economic status (SES) came from area-level census data and was assigned by residential postal codes. Generalized linear models with generalized estimating equations were employed to describe the relation between SES and injury rates and whether this relation changed over time. All-cause injuries were examined as well as injuries for motor vehicle collisions (MVCs), other vehicle injuries, self-inflicted injuries, assault, poisoning, injuries caused by machinery, sports injuries and falls.

RESULTS

Injury hospitalizations for children decreased steadily over the study period, from 1.07% to 0.51%. SES significantly predicted injury hospitalizations (p < 0.0001), children with lower SES showing higher rates. A significant SES by year interaction (p < 0.0001) indicated that the SES gradient for injury hospitalizations increased over time. Analysis by type of injury found a significant SES by year interaction for MVCs, self-inflicted injuries and falls; for MVCs and self-inflicted injuries the pattern (increasing SES gradient) was similar to that of hospitalization for all-cause injury. The pattern for falls was inconsistent.

CONCLUSION

Despite the overall drop in injury hospitalizations over time, the SES gradient in hospitalized injury rates has increased.

The Manitoba Healthy Baby Prenatal Benefit Program: who is participating?

BACKGROUND

Programs offering income supplements for lower-income pregnant women have been introduced in order to reduce the incidence of poor perinatal outcomes. This study used a population-based approach to examine the characteristics of mothers who received the Healthy Baby Prenatal Benefit in Manitoba.

METHODS

All women giving birth between August 2001 and April 2003 (n = 22,643) were studied using de-identified linked administrative data. Multivariate logistic regression was used to determine factors that predicted receipt of the benefit, adjusting for potential confounding effects. Separate regressions were run for all mothers, and for a group of mothers eligible to receive the benefit (N = 1962).

RESULTS

Almost 29% of mothers giving birth during the study period received the prenatal benefit. Mothers were more likely to receive the benefit if they: lived outside of Winnipeg; received income assistance during pregnancy; were younger at their first birth; were unmarried; made prenatal physician visits; experienced maternal depression; were having a first birth; and lived in the lowest income areas. Despite all being eligible, only 67% of non-Winnipeg and 80% of Winnipeg women receiving income assistance received the benefit. Factors related to benefit receipt for those eligible were: living in Winnipeg; making prenatal visits; not being a young teen at current birth; and experiencing a first birth.

CONCLUSION

It is important to look not only at the characteristics of benefit recipients but also at those not receiving the benefit, in order to develop strategies to reach those who may most need and benefit from the program.

The Manitoba Healthy Baby Prenatal Benefit Program: who is participating?

BACKGROUND

Programs offering income supplements for lower-income pregnant women have been introduced in order to reduce the incidence of poor perinatal outcomes. This study used a population-based approach to examine the characteristics of mothers who received the Healthy Baby Prenatal Benefit in Manitoba.

METHODS

All women giving birth between August 2001 and April 2003 (n = 22,643) were studied using de-identified linked administrative data. Multivariate logistic regression was used to determine factors that predicted receipt of the benefit, adjusting for potential confounding effects. Separate regressions were run for all mothers, and for a group of mothers eligible to receive the benefit (N = 1962).

RESULTS

Almost 29% of mothers giving birth during the study period received the prenatal benefit. Mothers were more likely to receive the benefit if they: lived outside of Winnipeg; received income assistance during pregnancy; were younger at their first birth; were unmarried; made prenatal physician visits; experienced maternal depression; were having a first birth; and lived in the lowest income areas. Despite all being eligible, only 67% of non-Winnipeg and 80% of Winnipeg women receiving income assistance received the benefit. Factors related to benefit receipt for those eligible were: living in Winnipeg; making prenatal visits; not being a young teen at current birth; and experiencing a first birth.

CONCLUSION

It is important to look not only at the characteristics of benefit recipients but also at those not receiving the benefit, in order to develop strategies to reach those who may most need and benefit from the program.

The incidence of methylphenidate use by Canadian children: what is the impact of socioeconomic status and urban or rural residence?

OBJECTIVE

To examine socioeconomic, demographic, and behavioural factors that influence the incidence of methylphenidate use among children aged 4 to 13 years.

METHOD

A total of 11,316 children, aged 2 through 11 years, from Cycle 1 (1994-95) of the National Longitudinal Survey of Children and Youth were followed up 2 years later in Cycle 2 (1996-97). The outcome measure was methylphenidate use in Cycle 2. Individual-level explanatory variables included sex, age, socioeconomic status (SES), mother's age at birth of child, lone-parent family status, parental working status, and hyperactivity-impulsivity and inattention probabilities. Area-level explanatory variables included income and rural or urban residence. We used hierarchical linear modelling to examine individual- and area-level factors that predicted methylphenidate use.

RESULTS

The strongest predictors of methylphenidate use were behavioural: children with high hyperactive-impulsive and (or) inattention behaviours in 1994, compared with children low on these behaviours, were 4.5 to 6 times more likely to use methylphenidate 2 years later. SES remained a significant predictor of the incidence of methylphenidate use, even when other significant predictors were held constant, with lower SES being associated with higher use. Area-level income also predicted methylphenidate use.

CONCLUSION

Even when children with similar behavioural symptoms and demographic characteristics were compared, socioeconomic factors had a significant impact on incidence of methylphenidate use.

Attention-deficit hyperactivity disorder in Manitoba children: medical diagnosis and psychostimulant treatment rates

OBJECTIVE

To describe physicians' diagnosis rates for attention-deficit hyperactivity disorder (ADHD) for children in the province of Manitoba and to describe the rate of psychostimulant medication use by these children.

METHODS

This descriptive study reviewed the computerized administrative records of physician visits and prescriptions dispensed to examine a population-based, cross-sectional cohort of children diagnosed with ADHD or prescribed stimulant medication, or both. We found 4787 children with a diagnosis of ADHD over a 24-month period or a prescription for stimulant medication over a 12-month period, or both. Rates were calculated by age, sex, region of residence, neighbourhood income level, and physician specialty.

RESULTS

Among Manitoba children, 1.52% received a medical diagnosis of ADHD and 0.89% received stimulant medication. Regionally, diagnosis rates for ADHD varied almost 4-fold, and over 8-fold for medications prescribed. Urban areas had higher rates than did rural areas, regardless of physician specialty. Diagnosis and prescription rates varied according to physician specialty, with the highest rates found among pediatricians. An income gradient was evident in rural areas, with rates of ADHD diagnosis and medication prescribed increasing with increased neighbourhood income level.

CONCLUSIONS

The pattern of regional variation found in this study suggests that the diagnosis and treatment of ADHD in Manitoba are influenced strongly by the practice styles of local physicians.

Monitoring health reform: a report card approach

During the past several years, budget cuts have forced hospitals in several countries to change the way they deliver care. Gilson (Gilson, L. (1998).

DISCUSSION

In defence and pursuit of equity. Social Science & Medicine, 47(12), 1891-1896) has argued that, while health reforms are designed to improve efficiency, they have considerable potential to harm equity in the delivery of health care services. It is essential to monitor the impact of health reforms, not only to ensure the balance between equity and efficiency, but also to determine the effect of reforms on such things as access to care and the quality of care delivered. This paper proposes a framework for monitoring these and other indicators that may be affected by health care reform. Application of this framework is illustrated with data from Winnipeg, Manitoba, Canada. Despite the closure of almost 24% of the hospital beds in Winnipeg between 1992 and 1996, access to care and quality of care remained generally unchanged. Improvements in efficiency occurred without harming the equitable delivery of health care services. Given our increasing understanding of the weak links between health care and health, improving efficiency within the health care system may actually be a prerequisite for addressing equity issues in health.

Monitoring the impact of hospital downsizing on access to care and quality of care

The most recent data used for monitoring the potential effects of bed closures in Winnipeg hospitals since 1992/93 found that despite downsizing, access to care was by no means compromised. Just as many patients were cared for in 1995/96 as in 1991/92. Changes in patterns of care included more outpatient and fewer inpatient surgeries, and a decrease in the number of hospital days. The number of high-profile surgical procedures, such as angioplasty, bypass, and cataract surgery, performed increased dramatically during downsizing. Quality of care delivered to patients, measured by mortality and readmission rates, was unaffected by bed closures. Of particular concern was the impact of downsizing on the two most vulnerable health groups--the elderly and Manitobans in the lowest income group. Access and quality of care for these groups also remained unchanged. However, those in the lowest income group spent almost 43% more days in hospital than those in the middle income group, and research demonstrates that these variations in hospital use across socioeconomic groups reflect real and important health differences and are not driven by social reasons for admissions. Finally, a large decrease in waiting time for nursing home placement underlines the relationship between downsizing and availability of alternatives to hospitalization.

The unintended and unexpected impact of downsizing: costly hospitals become more costly

OBJECTIVES

In this project we assessed the impact of 1992 budget cuts ($50 million, or approximately 7% of urban hospitals' budgets) on the relative costliness of Manitoba's hospitals. The cuts targeted the teaching hospitals, those institutions we had found to be particularly costly in a previous Manitoba Centre for Health Policy and Evaluation study.

RESULTS

Unexpectedly, we found that because budget cuts were smaller proportionately than the number of beds closed, the care at the teaching hospitals (as well as at several other hospitals) became relatively more, not less, costly. Also quite contrary to public perceptions, once other expenditures such as new hospital programs and expansions were accounted for, the actual change in urban hospital expenditures over the years compared was less than 1%.

CONCLUSIONS

The study highlighted the importance of monitoring program outcomes.

Managing health services: how the Population Health Information System (POPULIS) works for policymakers

OBJECTIVES

University-based researchers in Manitoba, Canada, have used administrative data routinely collected as part of the national health insurance plan to design an integrated database and population-based health information system. This information system is proving useful to policymakers for answering such questions as: Which populations need more physician services? Which need fewer? Are high-risk populations poorly served? or do they have poor health outcomes despite being well served? Does high utilization represent overuse? or is it related to high need? More specifically, this system provides decision makers with the capability to make critical comparisons across regions and subregions of residents' health status, socioeconomic risk characteristics and use of hospitals, nursing homes, and physicians. The system permits analyses of demographic changes, expenditure patterns, and hospital performance in relation to the population served. The integrated database has also facilitated outcomes research across hospitals and countries, utilization review within a single hospital, and longitudinal research on health reform. The discussion highlights the strengths of integrated population-based information in analyzing the health care system and raising important questions about the relationship between health care and health.

Private health care in Canada: savior or siren?

In canada, health care is publicly insured and available to all at no charge. Recently, financial pressures have threatened the system and led to considerable debate about how to save it. One proposal is to permit privately funded health care alongside the public system, resulting in what is popularly called a two-tiered system. This paper presents some of the arguments for and against two-tiered health care. Using as an example cataract surgery-a procedure that is available both publicly and privately-the authors look at some common beliefs about private health care in Canada. They conclude that the growth in private sector cataract surgery does not appear to be related to cutbacks or rationing, that private access does not necessarily shorten waiting times, and that, contrary to popular belief, it is not only the well-to-do who pay for private surgery in Canada.

Discharging patients earlier from Winnipeg hospitals: does it adversely affect quality of care?

OBJECTIVE

To determine whether decreasing lengths of stay over time for selected diagnostic categories were associated with increased hospital readmission rates and mean number of physician visits after discharge.

DESIGN

Retrospective descriptive study.

SETTING

The seven large (125 beds or more) acute care hospitals in Winnipeg.

PATIENTS

Manitoba residents admitted to any one of the seven hospitals because acute myocardial infarction (AMI), bronchitis or asthma, transurethral prostatectomy (TURP) and uterine or adnexal procedures for nonmalignant disease during the fiscal years 1989-90 to 1992-93. Patients from out of province, those who died in hospital, those with excessively long stays (more than 60 days) and those who were transferred to or from another institution were excluded.

OUTCOME MEASURES

Length of hospital stay, and rate of readmission within 30 days after discharge for all four categories and mean number of physician visits within 30 days after discharge for two categories (AMI and bronchitis or asthma.

RESULTS

The length of stay decreased significantly over the 4 years for all of the four categories, the smallest change being observed for patients with AMI (11.1%) and the largest for those with bronchitis or asthma (22.0%). The readmission rates for AMI, bronchitis or asthma, and TURP showed no consistent change over the 4 years. The readmission rate for uterine or adnexal procedures increased significantly between the first and second year (chi 2 = 4.28, p = 0.04) but then remained constant over the next 3 years. The mean number of physician visits increased slightly for AMI in the first year (1.92 to 2.01) and then remained virtually the same. It decreased slightly for bronchitis or asthma over the 4 years. There was no significant correlation between length of stay and readmission rates for individual hospitals in 1992-93 in any of the four categories. Also, no correlation was observed between length of stay and mean number of physician visits for individual hospitals in 1992-93 in the categories AMI and bronchitis or asthma.

CONCLUSIONS

Improving hospital efficiency by shortening length of stay does not appear to result in increased rates of readmission or numbers of physician visits within 30 days after discharge from hospital. Research is needed to identify optimal lengths of stay and expected readmission rates.

Variation in length of stay as a measure of efficiency in Manitoba hospitals

OBJECTIVE

To examine the efficiency of Manitoba hospitals by analysing variations in length of stay for patients with similar characteristics.

DESIGN

Retrospective study. Multiple regression analyses were used to adjust for patient (case-mix) characteristics and to identify differences in length of stay attributable to the hospital of admission for 14 specific, frequently encountered diagnostic categories and for all acute admissions.

SETTING

The eight major acute care hospitals in Manitoba.

PARTICIPANTS

Manitoba residents admitted to any one of the eight hospitals during the fiscal year 1989-90, 1990-91 or 1991-92. Patients transferred to or from another institution, those with atypically long stays and those who died in hospital were excluded.

OUTCOME MEASURE

Length of hospital stay.

RESULTS

The length of stay was strongly influenced by hospital of admission, even after adjustment for key patient characteristics. Excluding the most seriously ill patients and those with the longest stays, approximately 186 beds could potentially have been saved if each hospital had discharged its patients as efficiently as the hospital with the shortest overall length of stay.

CONCLUSIONS

A substantial proportion of days currently invested in treating acute care patients could be eliminated. At least some bed closures in Manitoba hospitals could be accommodated simply through more efficient treatment of patients in the remaining beds, without decreasing access to hospital care.

Development and training of referential communication in children with mental retardation

In referential communication, the speaker must communicate to the listener about how a referent is different from other stimuli (i.e., employ the "difference rule"--Whitehurst & Sonnenschein, 1985). In Experiment 1 we compared use of the difference rule by children with and without mental retardation matched for Quick Test MA. Participants with mental retardation were less likely to employ the difference rule. Experiment 2 demonstrated that perceptual feedback training, which teaches use of the difference rule, enhances referential communication of children with mental retardation.

Small lymphocytic lymphoma: a clinicopathologic analysis of 268 cases

We analyzed specimens from 268 patients with small lymphocytic lymphoma (SL) to identify prognostic factors significant for survival. These patients were staged and treated according to the protocols of the Cancer and Leukemia Group B, Eastern Cooperative Oncology Group, Southeastern Cancer Study Group, and the Southwest Oncology Group. Univariate analysis showed that a large-cell grade greater than I, WBC greater than 10,000/microL, hemoglobin (Hgb) less than 11 g/dL, age greater than or equal to 55 years, and failure to respond to treatment were all poor prognostic factors. Multivariate analysis showed that large-cell grade, age, degree of capsular invasion, and symptom type were independently associated with survival. Separate analyses of cases with and without leukocytosis indicated differences in survival. In patients without leukocytosis, age, presence or absence of anemia, and treatment response were significant prognostic variables; in patients with leukocytosis, large-cell grade, presence or absence of anemia, symptom type, and treatment response were significantly related to survival. Multivariate analysis showed that age was the only significant independent prognostic variable in patients without leukocytosis; in patients with leukocytosis, symptom type, large-cell grade, and bone marrow involvement were independently associated with survival. We conclude that several parameters, both clinical and pathologic, should be assessed at the initial diagnosis of SL to predict prognosis better.

Variability in interpretation of immunohistologic findings in lymphoproliferative disorders by hematopathologists. A comprehensive statistical analysis of interobserver performance

Eight hematopathologists independently reviewed 56 consecutive cases of benign and malignant lymphoproliferative disorders (LPD) to determine: (1) the degree of interobserver agreement on the interpretation of immunologic findings on fresh-frozen sections alone and on that of the immunologic findings in conjunction with corresponding hematoxylin and eosin (H & E)-stained histologic sections; (2) whether prior knowledge of morphologic characteristics influences the interpretation of immunohistologic sections; (3) whether immunologic phenotype could be predicted reliably based solely on study of histologic sections; and (4) the significance of immunologic data as an aid in the interpretation of histologic sections. The study was carried out in three independent review sessions consisting of (1) review of immunohistologic sections only, (2) review of the same immunohistologic sections together with histologic sections, and (3) review of the histologic sections alone. A consensus diagnosis was defined as agreement of five or more pathologists on the final diagnosis and identification of the immunophenotype. When the authors compared the total number of major disagreements in the first review session with those in the second, the accuracy of the determination of immunophenotype in the second session was clearly superior (P less than 0.05). Similarly, the total number of major disagreements in the second review session was significantly lower than that in the third review session (P less than 0.001). When histologic diagnoses in the second session were compared with those in the third session, it became apparent that the immunologic data helped the pathologist to correct major misinterpretations in 14 cases (25%). This study is the first to demonstrate quantitatively that (1) knowledge of morphologic features influences and greatly enhances the accuracy of the interpretation of immunologic findings, (2) the immunophenotype of LPD cannot be predicted based on morphologic findings alone, and (3) immunologic findings improve the accuracy of interpretation of histologic findings in situations in which a diagnosis cannot be made from morphologic features only.

Distinction between undifferentiated (small noncleaved) and lymphoblastic lymphoma. An immunohistologic study on paraffin-embedded, fixed tissue sections

The morphologic differentiation between malignant lymphoma of the small noncleaved cell (SNC) type and lymphoblastic lymphoma (LBL) is at times difficult, particularly when fresh tissue is not available for immunologic studies. We have examined the reactivities of a panel of monoclonal and polyclonal antibodies, including LN-1, LN-2, and antibodies to immunoglobulin light chains, leukocyte common antigen (LCA), Leu-M1, vimentin, S-100 protein, lysozyme, and alpha-1-antitrypsin, in paraffin-embedded, B5- and formalin-fixed tissue involved by SNC or LBL. The immunophenotypes in all of the cases included in this study had been characterized previously in fresh-frozen sections or cell suspensions. Among 21 samples of B5-fixed SNC, LN-1 was reactive in 17 and LN-2 in 18 cases. Among 13 B5-fixed LBL, LN-1 was reactive in two cases and LN-2 was reactive in two cases. Each of 20 B5-fixed samples of SNC was reactive with at least one of the antibodies, whereas 10 of the 13 B5-fixed samples of LBL were negative for both antibodies. Lesser reactivity was evident in formalin-fixed tissues, with only nine of 27 SNC specimens positive for LN-1 and 16 of 27 positive for LN-2. Most or all of the SNC and LBL samples were negative for immunoglobulin light chains, Leu-M1, vimentin, S-100 protein, lysozyme, and alpha-1-antitrypsin. The majority of both SNC and LBL were positive for LCA. We conclude that LN-1, preferably in combination with LN-2, can be used for distinguishing between SNC and LBL in paraffin-embedded, B5-fixed tissue when fresh tissue is not available.

Synthesis, processing, and secretion of the core-specific lectin by rat hepatocytes and hepatoma cells

A lectin, previously designated the Man/GlcNAc-specific lectin or mannan-binding protein, is found in rat liver and plasma. Analysis of the structural requirements for oligosaccharide binding indicated that the specificity of this lectin is directed primarily at the "core" and peptide region of glycopeptides (Maynard, Y., and Baenziger, J. U. (1982) J. Biol. Chem. 257, 3788-3794). We have examined synthesis and secretion of the core-specific lectin by primary rat hepatocytes and a rat hepatoma, H-4-II-E, utilizing pulse labeling with [35S]methionine, immunoprecipitation with a monospecific rabbit antibody raised against the purified lectin, and analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. A post-translational modification occurs between 10 and 40 min of chase which results in an increase in the Mr from 24,000 to 26,000. This modification is not due to asparagine-linked glycosylation or oligosaccharide processing. The kinetics of secretion are unusual. Secretion begins at 1 h of chase and proceeds linearly for approximately 8 h until a maximum of 70% of the lectin has been secreted. Secretion, but not the post-translational modification is inhibited by monensin. The pattern of synthesis and secretion in conjunction with the presence of the lectin in plasma indicate that it is a plasma protein of hepatocyte origin. The slow kinetics of secretion compared to other secretory proteins indicate an unusual mechanism for the segregation of the lectin from other secretory proteins and/or a different intracellular pathway for secretion.

Evidence for transmembrane modulation of the ligand-binding site of the hepatocyte galactose/N-acetylgalactosamine-specific receptor

The ligand-binding activity of the galactose/N-acetylgalactosamine-specific receptor (Gal/GalNAc receptor) present on the surface of hepatocytes can be modulated under a number of conditions in the intact cell. The carboxylic acid ionophores monensin and nigericin inhibit endocytosis by the Gal/GalNAc receptor in a concentration-dependent manner. Monensin at a concentration of 100 microM reduces the number of binding sites for asialo-orosomucoid and a tri-branched glycopeptide (F2) 5-10-fold; however, the number of Gal/GalNAc receptor subunits detected at the cell surface by a competitive radioimmunoassay and by immunoprecipitation of surface labeled receptor is not significantly altered. Replacement of NaCl in the medium with either N-methylglucamine or sorbitol to isotonicity also inhibits binding and endocytosis. The monensin, nigericin, N-methylglucamine, and sorbitol treatments have in common the ability to alkalinize the cytosol of the hepatocyte. None of these agents has any effect on binding by the isolated Gal/GalNAc receptor nor is the intracellular pH shift of such a magnitude that it would alter binding by the isolated Gal/GalNAc receptor. This has led us to conclude that the ligand-binding properties of the Gal/GalNAc receptor at the cell surface can be modulated in a transmembrane fashion by events other than those involving pH or Ca2+ regulation at the ligand-binding site itself. Such transmembrane modulation of ligand binding by the Gal/GalNAc receptor may provide a rapid and efficient mechanism for mediating ligand release and immediate return of the receptor to the cell surface.