Corrected Mortality Research Articles

Widening ethnic mortality disparities in New Zealand 1981–99

The aim of this paper is to determine the extent of undercounting of Mäori and Pacific deaths in New Zealand during the 1980s and 1990s, and to calculate corrected ethnic mortality and life expectancy trends. We calculated adjustment ratios for undercounting of Mäori and Pacific deaths (and over-counting of non-Mäori non-Pacific (nMnP) deaths) using the linked census-mortality data. These ratios were then used to calculate corrected mortality rates and life expectancies. Mäori deaths were underestimated by a quarter, and Pacific deaths by a third, during the 1980s and early 1990s. Undercounting was minor in the late 1990s following alignment of ethnicity collection on mortality data to approximate the census. Corrected mortality rates demonstrated 30% (males) and 26% (females) decreases among nMnP from 1980–84 to 1996–99, smaller decreases among Mäori (8% and 7%) and no clear change among Pacific people (9% decrease for males, 4% increase for females). The gap in life expectancy increased from an average of 7.7 years in 1980–84 to 10.8 years in 1996–99 for Mäori, and from 3.3 to 7.7 years for Pacific people, in comparison to nMnP people. Deaths among 45–64 and 65 plus year olds, and cardiovascular disease and cancer deaths, were the main contributors to these disparities. The economic reforms in New Zealand during the 1980s and early 1990s impacted harder upon Mäori and Pacific people in terms of unemployment and income, and are a likely explanation for the diverging mortality trends in this period. Both behavioural factors and health services probably also play a role, but in the absence of trend data by ethnicity, their contribution to diverging mortality trends is unknown. Internationally, our study demonstrates marked undercounting of Mäori and Pacific deaths. We strongly encourage researchers and custodians of vital statistics in other countries to investigate the possibility of undercounting of deaths by ethnicity.

Effectiveness of different species/strains of entomopathogenic nematodes for control of western flower thrips (Frankliniella occidentalis) at various concentrations, host densities, and temperatures

Abstract Entomopathogenic nematode (EPN) species/strains (Rhabditida: Steinernematidae and Heterorhabditidae) were tested at a concentration of 200 infective juveniles (IJs) per cm 2 against mixed soil-dwelling life stages (i.e., second-instar larvae, prepupae, and pupae) of the western flower thrips (WFT) Frankliniella occidentalis (Thysanoptera: Thripidae), in a plant growing substrate under laboratory conditions. The different EPN species/strains resulted in WFT corrected mortality (CM) values ranging between 2.6 and 60%. In general, Heterorhabditis spp. were more virulent than Steinernema spp. Increasing concentrations of selected EPN species/strains led to an increase in thrips CM, with significant differences among species/strains. Heterorhabditis indica LN2 caused higher CM than the other strains, with 30 and 90% as highest CM at the lowest and highest concentration tested, i.e., 100 and 1000 IJs cm −2 , respectively. In an experiment with different WFT densities, CM caused by Steinernema bicornutum negatively correlated with host density. However, with H. indica LN2, CM increased, though not always significantly, with increasing host densities. Generally, the effect of host density on efficacy of EPNs depended on concentrations. When tested over a range of temperatures, 25 °C was the optimal temperature for both H. indica LN2 and S. bicornutum . H. indica LN2, tropical in origin, and S. bicornutum , isolated from a more temperate environment, performed better at higher and lower temperatures, respectively.

Trend of cervical cancer mortality in Belgium (1954-1994): tentative solution for the certification problem of unspecified uterine cancer.

We investigated the evolution of mortality from cervical cancer in Belgium between 1954 and 1994 in terms of absolute number of deaths, and standardised and age-specific mortality rates. Changes over generations were summarised using the standardised cohort mortality ratio. Trend studies of cervical cancer mortality were hampered by certification problems. The number of deaths due to cancer of the uterine cervix is not known exactly since a substantial proportion of death causes are coded as cancer of the uterus without specifying the anatomic site: cervix or corpus uteri. This inaccuracy in codification has been corrected using distribution tables derived from countries where this certification problem is minimal. Trends in mortality from certified and corrected cervical cancers were compared. The corrected age-standardised mortality rate decreased continuously over the last 4 decades, from over 14 to 5 per 100,000 woman-years (slope -0.26/100,000 woman-years, 95% CI -0.28 to -0.24). Its slope is 3.1 times (95% CI 2.9-3.5) more important than for the rate of mortality from certified cervical cancer. In addition to the almost linear decrease, substantial nonlinear cohort influences were observed in certified and corrected mortality rates. The tendency of increasing mortality in women born after 1935 required particular attention. Nevertheless, the slope of the corrected recent cohort effect remained limited in Belgium, probably as a consequence of screening.

Grazer Frühgeborenenanalyse: Gewichtsperzentilen extrem Frühgeborener und prognostischer Wert des Geburtsgewichtes und sonographisch geschätzten Gewichtes

Purpose: Estimated fetal weight in very-low-birth-weight infants (VLBWI) frequently serves as a prognostic factor and as an aid for planning management of delivery. However, few data are available on the normal range of birth weight prior to the 32nd gestational week. Moreover, estimated fetal weight is subject to a mean error of 15-20%. Material and Method: Thus we calculated percentiles of birth weight, analyzed the prognostic significance of birth weight, and estimated fetal weight for the survival of VLBWI in 437 unselected single births. Results: The 3rd, 10th, 50th, 90th and 97th percentiles between 24 and 32 week's gestation were 514-997 g, 526-1106 g. 710-1590 g, 888-1964 g and 1106-2082g, respectively. Thus, a 1000 g newborn could be of a gestational age of 24-32 gestational weeks (95th and 10th percentile, respectively). The estimated fetal weight had a mean error of ±15%. The highest deviation of - 560 g corresponds to a variation of 5 gestational weeks (estimated 1100 g, acutal 1660 g). The uncorrected and corrected neonatal mortality rates were 16.5% and 7%, respectively (corrected by malformations and abortions). The uncorrected mortality rate decreased from 61% (wk 23/24) through 29% (wk 25/26), 13% (wk 27/28), 9% (wk 29/30) to 8% (wk 31/32), respectively. The respective corrected mortality rate decreased continuously from 25% to 3%. In contrast, the mortality rate was inconsistent between a birth weight of 1500 g after weight stratification in 250 g steps (54%, 19%, 21 %, 6%, 6%). While there was a significant correlation between gestational age and neonatal mortality rates (R=0,94; p<0,02), no correlation could be shown between birth weight and the mortality rate (R = 0.8; p = 0.11). Conclusion: Because of the lack of specificity of birth weight for gestational age and consequently fetal maturity, and because of the large systematic error in estimating fetal weight, the management of VLBWI should be based on the gestational age rather than on the estimated birth weight.

Maternal and Neonatal Outcome in Major Placenta Previa

A review of 96 cases of major degree placenta previa managed in King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia between 1988 and 1991 was carried out. A policy of "expectant management" with confinement in the hospital, blood transfusions in the antenatal period and cesarean section as the exclusive mode of delivery at maturity was practiced. Tocolytics and cervical cerclage were not used. There was no maternal mortality. The neonatal fetal mortality rate was 41.6/1000 while the incidence of neonatal respiratory distress syndrome was 18.7%. The results are compared with similar studies done elsewhere and analyzed with a view to improving the fetomaternal outcome.

The relationship of increased amniotic fluid volume to perinatal outcome

We studied a group of 135 patients with polyhydramnios diagnosed on the basis of ultrasonic findings (greatest vertical diameter of the liquor column ⩾8.0 cm) between 32 and 36 weeks gestation (study group). We compared the obstetric characteristics and perinatal outcome of the study group with a similar number who constituted our control group. The incidence of women aged 20 years or less was higher in the study group (8.9%) compared with 4.5% in the control group. Of the 135 patients who were diagnosed to have polyhydramnios ultrasonically, the clinical diagnoses prior to referral for ultrasonic scanning, were, suspected large for date fetuses in 34 patients (25.2%), clinically suspected polyhydramnios in 28 (20.7%), gestational diabetes in 21 (15.6%) and insulin dependent diabetes in 6 (4.4%) compared with 13.3%, 5.2%, 3.0% and 0.7%, respectively in the control group (P < 0.05). Preterm delivery occurred in 11.1% in the study group compared with the incidence of 6.7% in the control group. The incidence of fetal distress, low Apgar Score, macrosomic infants, major fetal anomalies, gross and corrected perinatal mortality rate and admission to special/intensive care nursery was significantly higher in the study group compared with that of the control (P < 0.01). We found ultrasonic examination is a reliable technique to assess the amount of amniotic fluid volume and it alerts the clinician to possible future problems in pregnancy, labor and neonatal period.

Mode of delivery in multiple birth of higher order.

A retrospective review of triplets delivered at a Boston perinatal center from 1977 to 1986 was performed. Comparison was made between this group (study group) and previously published data on triplets in our institution (control group). Since 1977 there was a more liberal use of abdominal delivery. Cesarean sections (CS) of all triplets with malpresentation was our protocol. Of the 15 sets of triplet pregnancies in the study group, 11 were delivered by CS and 4 by vaginal delivery, vs only 1 CS in the control group which consisted also of 15 triplets. The corrected mortality rate in the study group was lower than in the control group (2.6% vs 7.1%) but did not reach statistical significance. Apgar scores at 1 and 5 minutes were significantly higher in the study group (P less than 0.002). Apgar scores for the third triplet were also higher in the study group (P less than 0.05). In comparing the combined mortality and morbidity between the study group and the control group, no difference was found in the first triplet, but those of the second and third triplets were significantly lower in the study group. Of interest is the finding that the combined mortality and morbidity was not different statistically among the first, second, and third triplets in the study group, while in the control group an increase from the first to the third triplet was noted (21%, 31%, and 43%, respectively). A more liberal approach toward abdominal delivery of pregnancies of higher fetal number is advocated.

Nonimmune hydrops fetalis: Clinical experience and factors related to a poor outcome

Twenty-one cases of nonimmune hydrops fetalis diagnosed at the Medical College of Georgia during a 2-year period are presented. All fetuses satisfied strict diagnostic criteria and were evaluated according to a standard protocol. The corrected mortality rate was 95% with pulmonary hypoplasia being the most common cause of perinatal death. The mean gestational age at diagnosis was 24.8 weeks; in 57% of the cases the cause of nonimmune hydrops fetalis was identified. Fifteen fetuses had serial ultrasound assessment and in 19 cases postnatal evaluation was performed. Two factors that consistently conveyed a poor perinatal outcome were ultrasonographic evidence of malformation and/or the presence of persistent pleural effusions. A method for the quantification of fetal pleural effusions is presented and its clinical relevance is discussed.

Vaginal breech delivery of selected infants weighing more than 2000 grams: A retrospective analysis of seven years' experience

This retrospective study analyzes 580 term and near-term singleton pregnancies complicated by breech presentation from 1976 through 1982. Vaginal delivery was achieved in 174 patients (30%), 135 of which were selectively allowed a trial of labor. Six infant deaths occurred (1%); all were neonatal deaths directly related to lethal congenital anomalies, for a corrected neonatal mortality rate of 0%. No significant difference was found in the incidence of low Apgar scores, traumatic birth injury, or requirement for neonatal resuscitation between those infants delivered by cesarean section and those delivered vaginally. Although no maternal deaths occurred, cesarean section was associated with a 38-fold increase in significant maternal morbidity. These data suggest that with careful patient selection and fetal monitoring, vaginal delivery of the term or near-term breech infant remains a real alternative to routine cesarean delivery of all breech infants. A selection and management protocol is proposed.

Smoking and myocardial infarction: secondary prevention.

This prospective study examines the question 'Is it too late to stop smoking cigarettes once you have had a myocardial infarction?' One hundred and nineteen cigarette smokers (90 men, 29 women) who survived their first myocardial infarction for one month were followed for five years or until their death if earlier. The age corrected mortality rate of men who continued to smoke cigarettes was 2.2 times the age corrected mortality rate of those who stopped smoking after their infarct. The women who continued to smoke had 2.4 times the age corrected mortality of those who stopped smoking. The age and sex corrected mortality rates for the combined group of men and women show that those who stopped smoking after their infarction have 55% of the mortality of those who continued to smoke (P less than 0.05). These results suggest that smoking is not merely a 'risk factor' for myocardial infarction but is also a causal factor whose effects can be avoided by both men and women after an initial myocardial infarction.

The Bedford Survey: Ten year mortality rates in newly diagnosed diabetics, borderline diabetics and normoglycaemic controls and risk indices for coronary heart disease in borderline diabetics

Mortality rates from coronary heart disease and from all causes have been ascertained over ten years in three groups of people participating in the Bedford Survey--newly-diagnosed diabetics, borderline diabetics and control subjects with normal glucose tolerance. Age corrected mortality rates, from all causes and coronary heart disease, were highest in the diabetics and intermediate in the borderline diabetics and in both groups were similar in men and women. When statistical allowance was made for baseline differences in age, blood pressure and obesity, female borderline diabetics still had a significantly increased risk over their controls of death from 'all causes'. Much of the difference appeared to be due to a relative excess of deaths due to coronary heart disease. It is concluded that borderline diabetes (or impaired glucose tolerance) is associated with a relatively greater increase in mortality risk in women than men. During the 10-year follow-up of the Bedford borderline diabetics, coronary heart disease morbidity and mortality rates were similar in men and women. Age at entry to the study was the major independent and significant predictor of mortality from all causes. The level of systolic blood pressure and current cigarette smoking at baseline were statistically significant predictors only of mortality due to coronary heart disease.

Comparing the Early Mortality Rates of the Local Authorities in England and Wales

Overall mortality rates of sub-populations are frequently adjusted for factors like sex and age to make them more directly comparable. In this paper we are concerned with the problem of adjusting various early infant mortality rates of the Local Authorities of England and Wales for variations in their circumstances. For example, the proportion of infants of low birth weight (which is well correlated with perinatal mortality rate) shows a strong North-South contrast, and this needs to be taken into account. The usual direct and indirect methods of adjustment are not suitable here since we intend to correct for a relatively large number of factors. Instead we employ regression analysis, the residuals in effect being the corrected mortality rates. In most regression analyses chief interest lies in the estimated model, residuals often being discarded as worthless once the fit has been judged adequate and error estimated. In this paper by contrast they are of prime importance and we go to considerable lengths to ensure that the order of merit table that they produce is robust. With a stepwise procedure to ensure that we correct only for worthwhile explanatory variables out of our list of 86, Bath and Carlisle are identified as having extremely high corrected perinatal mortality rates and Hull and Hartlepool exceptionally low. Lists of outstanding Authorities change with the mortality rate used quite strongly. In a few cases we find that Authorities with low corrected rates for one grade of mortality (late neonatal, say) have high corrected rates for another (postneonatal, for example). Explanation levels are generally high, sometimes reaching 90 per cent or more. As for important regressor variables, it is found that those describing social and economic circumstances dwarf those representing medical services for all of the mortality rates used, though to be fair, these are inadequately represented in our data set. As far as perinatal mortality rate is concerned, the proportion of low weight infants, not surprisingly, turns out to be all-important.

Prolapse of the umbilical cord.

Two series of cases of umbilical cord prolapse are submitted. One comprises 97 cases and the other 64. The total corrected mortality rate was 13.0% and 34.5% respectively, the mature corrected mortality rate 1.5% and 20.0%. The total mortality for breech presentations with prolapsed cord was 19.2% and 23.8% respectively. In cephalic presentations the mortality rate was 10.3% and 54.3% respectively. This difference in mortality is explained by a more active attitude in the department having the lower mortality, where the diagnosis was more often made by vaginal examination, the delivery was more rapid, and the use of Caesarean section more common.

Care of the Infant with Haemolytic Disease Due to Rh Incompatibility*

SummaryThe routine care of infants suffering from haemolytic disease of the newborn has been outlined, with particular reference to exchange transfusion.The management of complications which have been observed in these infants has also been discussed.A series of 293 Rh‐positive infants from iso‐immunized mothers has been briefly reviewed in relation to neonatal mortality. The corrected mortality rate was 6.2%.

Continuous caudal analgesia and anesthesia in obstetrics: A critical evaluation of 510 consecutive cases

1. Five hundred and ten patients in whom caudal analgesia was attempted were studied.2. Eighty per cent of patients in labor were found to be suitable for caudal analgesia with 97.5 per cent complete success.3. An increased incidence in the use of oxytocic agents and operative obstetrics was found.4. The advantages of caudal analgesia with elective induction of labor are stressed.5. Three babies were lost, of whom 2 had congenital abnormalities incompatible with life. This gives a corrected neonatal mortality rate of 0.2 per cent.

Mortality of acute infantile diarrhea at the Louisville General Hospital from 1943 to 1947

Summary The mortality rate of acute diarrhea of infants varies greatly duringdifferent months or years. From 1943 through 1946, 570 patients with severe acute infantile diarrheawere admitted to the Louisville General Hospital. Sixty-two of the patients died. The death rate was 10.92 per cent, and the corrected mortality rate was 7.5 per cent.

Results In the Treatment of Meningococcic Meningitis with Antitoxin and Sulfonamide Drugs

Summary An over-all mortality rate of 13.2 per cent was obtained in 309 patients treated with a combination of sulfonamide drugs and antitoxin. A corrected mortality rate of 8.8 per cent was obtained when we excluded those patients who were dead on arrival or who were moribund and died within forty-eight hours. This mortality rate of 8.8 per cent would be even less (that is 7.6 per cent) if we would exclude such patients as actually died from some other conditions although the latter were initiated by the infection itself. In general practice, physicians should strive for the same low mortality rate as obtained by the military, but it must be remembered that the civilian patient may be of any age and have an underlying pathologic condition which makes recovery almost impossible.

Results in the treatment of meningococcic meningitis with antitoxin and sulfonamide drugs

<h2>Summary</h2> An over-all mortality rate of 13.2 per cent was obtained in 309 patients treated with a combination of sulfonamide drugs and antitoxin. A corrected mortality rate of 8.8 per cent was obtained when we excluded those patients who were dead on arrival or who were moribund and died within forty-eight hours. This mortality rate of 8.8 per cent would be even less (that is 7.6 per cent) if we would exclude such patients as actually died from some other conditions although the latter were initiated by the infection itself. In general practice, physicians should strive for the same low mortality rate as obtained by the military, but it must be remembered that the civilian patient may be of any age and have an underlying pathologic condition which makes recovery almost impossible.