Infant mortality: a practical approach to the analysis of the leading causes of death and risk factors

The analysis of infant mortality data provides an opportunity for developing preventive strategies to improve this indicator of a population's health. All infant deaths in North Carolina during a 5-year period (1980 through 1984) were analyzed using the International Classification of Diseases, 9th revision (ICD-9), and a system for linked birth and death records that allows the analysis of birth certificate information on deaths. Causes of death were aggregated based on common etiology such as prematurity or obstetric-related conditions rather than the more traditional organ system taxonomy of the ICD-9 codes. Analyses were carried out separately for very low birth weight (less than or equal to 1500 g), moderately low birth weight (1501 through 2500 g), and normal birth weight (greater than 2500 g) babies. Maternal characteristics identified from the birth certificate were also compared with the different causes of death. Prematurity-related conditions accounted for 37.5% of all deaths, ranking far above the 17.4% for congenital anomalies and 12.9% for sudden infant death syndrome. For normal birth weight babies, sudden infant death syndrome ranked first, followed by congenital anomalies and nonperinatal infections. For the moderately low birth weight babies, congenital anomalies ranked first, with sudden infant death syndrome second and prematurity-related conditions third. For the very low birth weight babies, prematurity-related conditions accounted for nearly 70% of the deaths, with obstetric conditions and congenital anomalies ranking second and third, respectively. Maternal risk factors identified an overrepresentation of nonwhite, unmarried, and young teenage mothers and mothers with less than adequate prenatal care.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prader-Willi syndrome in Victoria: mortality and causes of death

Aim: The aim of this study was to describe the rates, predictors and causes of mortality in a population sample of individuals with Prader–Willi syndrome (PWS). Methods: One hundred sixty‐three individuals with PWS (90 males and 73 females, ages: 3 weeks to 60 years) were identified from the Victorian PWS Register. Information on demographics, age at diagnosis, genetic mechanism, age at which obesity developed and last known body mass index measurement were extracted. Notification and causes of death were obtained through linkage with Australian national and state of Victoria death indexes. Survival analysis was used to estimate the probability of survival and the effect of obesity on survival. Mortality rate ratios were calculated to investigate the effect of the factors listed above on mortality. Results: Fifteen deaths were recorded (nine males and six females), corresponding to an 87% probability of survival to 35 years. The probability of survival was significantly lower for individuals with known obesity (P= 0.03), but there was no strong evidence for an effect on survival for the other factors studied. Cardiac or respiratory conditions were common causes of death after the age of 15 years. Conclusions: The effect of known obesity on the probability of survival and the causes of death reported in this and other studies suggest an important association between obesity and early death in adults with PWS. This finding highlights the critical nature of preventative and intervention strategies aimed at minimising the effects of hyperphagia in individuals with PWS.     

Diagnostic value of radiography in cases of perinatal death: a population based study

Objective: To examine the yield of radiographic abnormalities in a population based set of perinatal deaths, the diagnostic value of whole body postmortem radiographs in the same set, and previous factors that may increase the proportion of useful examinations. Design: Retrospective population based study. Setting: A region of Norway. Patients: All infants from a well defined geographical area who were stillborn or had died soon after birth over an 11 year period (n=542), who had routinely undergone whole body radiography and autopsy. Main outcome measures: (a) Proportion of cases with abnormal radiographic findings. (b) Proportion of abnormal radiographs providing new information that was useful for postmortem diagnosis. Results: Radiographs were abnormal in 162/542 cases (30%). These provided new information about, but did not help to confirm, the pathological process leading to death in 14/162 (8.6%), may have helped to confirm, but not establish, the cause(s) of death in 1/162 (0.6%), and were of vital importance for establishing the cause(s) of death in 5/162 (3.1%). Among infants with external malformations, the proportion of useful radiographs was 12/100 (12%), and among the remainder it was 8/436 (1.8%), a difference of 10.2% (95% confidence interval 3.7% to 16.7%; data missing for six cases). Conclusions: The diagnostic value of postmortem radiography in this population based set was low. However, radiographic findings were of vital importance for establishing the cause(s) of death in 5/542 cases (0.9%).     

Cerebral palsy in Victoria, Australia: mortality and causes of death

OBJECTIVE: To study the causes of death and the characteristics of children with cerebral palsy that had died over a 25-year period in Victoria, Australia. METHODOLOGY: Names of children that had died were collected from the Victorian Cerebral Palsy Register. Their hospital records were studied and information was gathered about age of death, motor impairment, the presence or absence of associated disabilities and cause of death. RESULTS: One hundred and fifty-five children had died during the period 1970-95. The majority of children had severe spastic quadriplegia, intellectual disability and epilepsy. The predominant cause of death was pneumonia, although for many children who died at home the cause was unknown. CONCLUSIONS: Children with cerebral palsy are a diverse group and those with a severe motor deficit have a reduced life expectancy. Lung disease remains an important cause of morbidity and mortality for this group. Further information about the causes of death is needed, particularly for those children that die at home.     

Neuroblastoma in southern Brazil: an 11-year study

The authors report on the incidence and clinical characteristics of neuroblastoma in southern Brazil. The aims of the study were to evaluate the age at diagnosis, tumor stage, MYCN status, and tumor histopathology, and to relate these factors to survival. All patients with neuroblastoma, 15 years old or younger (n = 125), admitted to the three major pediatric oncology hospitals in the state of Parana over a period of 11 years (between January 1990 and December 2000), were included in the analysis. All patients were followed for at least 5 years. In addition, a FISH evaluation for MYCN status was conducted in a subset of 34 tumors. Overall survival for tumor stages 1, 2, 3, and 4 was 100%, 72%, 59%, and 17%, respectively. Sixty-two percent (77/125) of all patients were older than 2 years; these represented 71% (57/80) of the patients with stage 4 disease. Children who presented with an unfavorable histopathology had a significantly worse prognosis (20% survival) than children with a favorable histopathology (67% survival). MYCN amplification was detected most commonly in stages 3 and 4 tumors (13/16). These data showed a delayed diagnosis of neuroblastoma in children in southern Brazil, and consequently survival was considerably lower in these patients.     

Determinants of neonatal mortality in Rural Haryana: A retrospective population based study

Objective  

To identify the determinants of neonatal mortality.     

Excess risk of mortality in very low birthweight triplets: a national,population based study

BACKGROUND: Neonatal morbidity and mortality differ between singletons, twins, and triplets. OBJECTIVE: To evaluate whether plurality is associated with excess risk of neonatal morbidity and poor outcome (death, chronic lung disease, or adverse neurological findings) in very low birthweight (VLBW) infants from a national, population based cohort. METHODS: The Israel national VLBW infant database has prospectively collected extensive perinatal and neonatal data on all liveborn VLBW infants since 1995. The study sample (n = 5594) consisted of all singletons (n = 3717) and all complete sets of twins (n = 1394) and triplets (n = 483) born during 1995-1999. To account for differences in case-mix, both univariate and multivariate comparisons that included confounding variables such as antenatal steroid treatment and mode of delivery were performed for each of the outcome variables. RESULTS: There was a small inverse correlation between gestational age (GA) and birth weight (BW) and the number of fetuses (singletons: GA 28.9 (2.6) weeks, BW 1096 (269) g; twins: GA 28.4 (2.3) weeks, BW 1062 (271) g; triplets: GA 28.5 (2.4) weeks, BW 1049 (259) g). Triplets were significantly more likely to have been conceived following fertility treatments, to have received antenatal steroids, and to be delivered by caesarean section. Respiratory distress syndrome was significantly more common in twins and triplets in spite of the increased exposure to antenatal steroids. Multivariate logistic regression analysis using all significant perinatal covariates showed that triplets were at increased risk of death (odds ratio (OR) 1.54, 95% confidence interval (CI) 1.13 to 2.11), but not of adverse neurological outcome (OR 1.29, 95% CI 0.91 to 1.85) or chronic lung disease (OR 0.69, 95% CI 0.46 to 1.02). CONCLUSION: Despite considerable differences in the incidence of confounding variables between the groups, VLBW triplets are at increased risk of death compared with twins and singletons. In addition, VLBW twins and triplets more often have respiratory distress syndrome but not chronic lung disease or adverse neurological findings.     

Breast feeding duration in consecutive offspring: a prospective study from southern Brazil

The association between breast feeding duration in two consecutive pregnancies was studied in a prospective study in southern Brazil. In a population-based sample of 5960 women giving birth in 1982, 1386 delivered a second child within 4 years. The data were analyzed using life table techniques. The duration of breast feeding of the second child increased directly according to the duration the previous child had been breast fed. In particular, when the previous child had been breast fed for 6 months or more, the subsequent child was clearly more likely to be breast fed. However, when the previous child had been breast fed for under 6 months, the differences among subsequent children disappeared after 3-6 months. These differences were still present after stratification by family income, maternal education and parity. Mothers with a previous unsuccessful or problematic breast feeding experience should receive special priority in promotion campaigns.     

Racial differences in neonatal mortality. What causes of death explain the gap?

To examine further the differences in birth-weight-specific neonatal mortality rates between ethnic groups, we studied causes of death for infants of white, black, United States-born Hispanic, and Mexican-born Hispanic women using linked California birth-death records from 1981 to 1983. Black infants of low birth weight had considerably lower neonatal mortality rates from respiratory distress syndrome and congenital abnormalities. In the normal birth-weight category, however, black neonatal mortality rates for most conditions were higher than those for whites. The greatest differences between Mexican-born Hispanic and white neonatal mortality rates were seen for other respiratory conditions and trauma/hypoxia/asphyxia. These differences were most marked in the 1500- to 2499-g and greater than or equal to 2500-g birth-weight categories. Attempts to lower the neonatal mortality rate for black infants of normal birth weight may require providers to focus on both broad preventive measures and improved perinatal management. In contrast, improvements in perinatal management among Mexican-born Hispanics may produce improvement in the neonatal mortality rate for this group.     

Permanent sequelae in sports injuries: a population based study.

AIM: To identify permanent sequelae after sports injuries in children and adolescents. METHODS: In 1985, a prospective register was drawn up of all sports related injuries reported that year by the residents of Trieste, Italy aged 6-15 years. Moderate to severe injuries (scoring >/= 2 on the abbreviated injury scale (AIS)) were the object of a longitudinal clinical study. In 1988, 30.9% of the 220 subjects enrolled had sequelae. A further follow up was undertaken in 1997. RESULTS: The follow up in 1997 involved 54 subjects (26 girls; average age 24.5 years). Subjective and objective sequelae, by now considered to be permanent, were found in 61.1%, corresponding to 15% of the AIS >/= 2 injuries recorded in 1985. The prevalence of sequelae was similar in the two sexes, in relation to the child's age at time of injury, and in the different sports practised. It was higher in relation to the severity of the lesion (89% of AIS 3 injuries examined, 56% of AIS 2 injuries) and to the type of lesion and its location. With regard to AIS >/= 2 injuries, permanent sequelae were found in 50% of ankle fractures, 43% of elbow fractures, 33% of leg/foot fractures, 25% of knee sprains, and 23% of ankle sprains. CONCLUSIONS: The frequency of sequelae in sports injuries in children and adolescents is high. The risk appears to be connected to certain anatomical and functional age characteristics. Prevention strategies should include specific assessment of physical fitness and adequate follow up after the accident, particularly rehabilitation.     

Persistent nocturnal cough in childhood: a population based study.

A cross sectional epidemiological study was carried out to investigate the validity of persistent nocturnal cough (PNC) as an independent marker of childhood asthma. A screening questionnaire on respiratory symptoms was applied to 4003 children attending primary schools in Aberdeen, after which 799 symptomatic children and a random selection of 229 asymptomatic children were invited to attend for a diagnostic interview. Six hundred and seven (359 boys and 248 girls) symptomatic children and 135 asymptomatic children (57 boys and 78 girls) were selected from the screening questionnaires. Of 607 children with respiratory symptoms when interviewed, 27 (nine boys and 18 girls) had isolated PNC, and 97 (51 boys and 46 girls) had multiple symptoms (polysymptomatic asthma). The incidence of prematurity was highest in the group with PNC (19%). The prevalence of hay fever in children with PNC (11%) was similar to that of the asymptomatic group (15%) and less than that in the group with polysymptomatic asthma (41%). Eczema was twice as common in the PNC (19%) as in the asymptomatic children (10%) but only half as common in the polysymptomatic asthma group (35%). The prevalence of a parental history of hay fever was similar in all three groups. The prevalence of a parental history of eczema was similar in the PNC (7%) and asymptomatic (7%) groups but higher in the polysymptomatic asthma group (22%). The prevalence of a history of parental asthma was 30% in children with PNC, 13% in the asymptomatic group, and 42% in those with polysymptomatic asthma. The parents of three (11%) children with PNC were aware of a diagnosis of asthma; two of these children (7%) were on inhaled bronchodilator treatment and one (4%) was on a slow release theophylline preparation. Using a stepwise discriminant analysis procedure, in 18 (67%) children with PNC predicted membership was in the asymptomatic group and only nine (33%) children with PNC were grouped into the polysymptomatic asthma category. It is concluded that the clinical features of children with PNC resembled those of the asymptomatic population more closely than those of the polysymptomatic asthmatic population. In this age group PNC, in the absence of wheeze, shortness of breath or tightness in the chest, is likely to be a manifestation of atypical or hidden asthma in only a minority of cases.     

Prevalence and causes of congenital microcephaly in the absence of a Zika virus outbreak in southern Brazil

ObjectiveThe aim of this study was to identify the causes of congenital microcephaly in Rio Grande do Sul, a state in southern Brazil, where no ZIKV outbreak was detected, from December 2015 to December 2016, which was the period when ZIKV infection was at its peak in northeast Brazil.MethodsThis was a cross-sectional study where all notifications of congenital microcephaly in the state of Rio Grande do Sul were included for analysis. Evaluation of cases followed the guidelines of the Brazilian Ministry of Health. Dysmorphological and neurological evaluations were performed by a specialized team, and genetic tests and neuroimaging were performed when clinically indicated. STORCH infections were diagnosed using standard tests. ZIKV infection was diagnosed through maternal serum RT-PCR and/or neuroimaging associated with clinical/epidemiological criteria.ResultsFrom 153 744 registered live births in the study period, 148 cases were notified, but 90 (60.8%) of those were later excluded as “non-confirmed” microcephaly. In the 58 confirmed cases of microcephaly (prevalence = 3.8/10 000 live births), congenital infections (syphilis, toxoplasmosis, cytomegalovirus, and ZIKV) constituted the predominant etiology (50.0%), followed by isolated CNS (15.5%), and genetic syndromes (10.3%). Congenital ZIKV syndrome (CZS) with typical phenotype was diagnosed in three cases (5.2% of all confirmed microcephaly cases or 10.4% of all congenital infections).ConclusionIn Rio Grande do Sul, where no outbreak of ZIKV infection was recorded, congenital infections were the leading cause of congenital microcephaly, and the attributable risk for CZS in the etiology of microcephaly was 5.2%.