Seasonality of preterm birth in the Collaborative Perinatal Project: demographic factors

Marked circannual variation in the incidence of preterm birth, adjusted for the normal seasonal fertility rate, was observed in data from the Collaborative Perinatal Project collected at 12 urban university centers during 1959-1966 (p less than 10(-5). The variation in monthly preterm birth rates ranged from a trough of 64% in May to a peak of 144% in September. This is considerably greater seasonal variation than found in most previous studies, which used differing definitions of prematurity. The seasonal trend was present for maternal age groups 22-26 years (p less than 0.005) and greater than 26 years (p less than 0.005), for Bureau of the Census socioeconomic index 3.6-4.9 (p less than 10(-4) and greater than 4.9 (p less than 0.01), for those living in northern states (p less than 10(-4), for married gravidas (p less than 10(-6), for blacks (p less than 0.05) and whites (p less than 0.001), but not for those less than age 22, those with socioeconomic index less than 3.6, those living in southern states, and those not married. Thus, preterm birth was seasonal in the population studied, and the seasonal factor was more evident in demographic groups less predisposed to deliver preterm. These findings may have implications for the pathogenesis of a portion of premature deliveries, and should be considered in the design of studies related to the pathogenesis of preterm birth.     

High-specificity in-situ hybridization. Methods and application.

We describe a technique of in-situ hybridization using oligonucleotide probes employing the expression of immunoglobulin VH genes as a model. Optimal conditions for hybridization with the 35S-labeled oligonucleotide probes were established with monoclonal B-cell lines that express VH genes of known nucleic acid sequence. The range of sensitivity and specificity achieved with this technique is documented. Under conditions of high stringency, this method can detect the expression of highly related VH hypervariable regions.     

Comparison of continuous ambulatory peritoneal dialysis and hemodialysis patient survival with evaluation of trends during the 1980s.

To evaluate the mortality of continuous ambulatory peritoneal dialysis (CAPD) patients relative to hemodialysis (HD) patients, all Michigan residents 20 to 59 yr of age who initiated therapy for ESRD during the 1980s (N = 4,288) were studied. The study population was stratified by primary renal diagnosis (glomerulonephritis, hypertension, diabetes, other), and analyses were conducted within each group by Cox proportional hazards methods controlling for age, race, sex, and year in which chronic dialysis was initiated. Intent-to-treat (ITT) and treatment history (RxHx) censoring criteria were used. For patients with hypertension or other reported causes of ESRD, there was no significant difference in CAPD and HD patient mortality (relative risk (RR) = 0.99 and 1.05, respectively). In the ITT analysis, both glomerulonephritic (RR = 0.73; P = 0.10) and diabetic patients using CAPD experienced mortality rates lower than their HD counterparts. Among diabetics, this difference ranged from a RR of 0.40 to 0.70, being lowest for younger diabetics and statistically significant (P < or = 0.05) for ages 20 to 52 yr. Evaluation of mortality trends showed a significant (P < 0.01) decrease in diabetic CAPD mortality rates during the decade, whereas diabetic HD mortality rates increased (P = 0.06). Among diabetics, men had higher mortality rates than women (ITT--RxHx; RR = 1.22 to 1.27; P < 0.001) and white patients had higher mortality rates than black patients (ITT--RxHx, RR = 1.34 to 1.44; P < 0.001). Differences in mortality by sex and race were not found among nondiabetics, but mortality did increase significantly with age in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

SRTR Center-Specific Reporting Tools: Posttransplant Outcomes

Measuring and monitoring performance—be it waiting list and posttransplant outcomes by a transplant center, or organ donation success by an organ procurement organization and its partnering hospitals—is an important component of ensuring good care for people with end-stage organ failure. Many parties have an interest in examining these outcomes, from patients and their families to payers such as insurance companies or the Centers for Medicare and Medicaid Services; from primary caregivers providing patient counseling to government agencies charged with protecting patients.
The Scientific Registry of Transplant Recipients produces regular, public reports on the performance of transplant centers and organ procurement organizations. This article explains the statistical tools used to prepare these reports, with a focus on graft survival and patient survival rates of transplant centers—especially the methods used to fairly and usefully compare outcomes of centers that serve different populations. The article concludes with a practical application of these statistics—their use in screening transplant center performance to identify centers that may need remedial action by the OPTN/UNOS Membership and Professional Standards Committee.     

Impact of major co-morbidities on mortality and complications after gastric bypass

BACKGROUND: We hypothesized that major co-morbidities affect survival and complications after gastric bypass. METHODS: A total of 1465 patients undergoing laparoscopic and open gastric bypass between 1995 and 2002 were studied. Patients with a body mass index >or= 35 kg/m(2) and major co-morbidities (group 1, n = 1045) were compared with patients with a body mass index >or= 40 kg/m(2) with minor/no co-morbidities (group 2, n = 420). RESULTS: Group 1 patients were older (43 versus 36 years, P < 0.001) and had a greater BMI (53 versus 50 kg/m(2), P < 0.001). Early postoperative complications were greater in group 1 than in group 2 and included leaks (4.1% versus 1.2%, P < 0.0032) and wound infections (3.9% versus 1.4%, P < 0.0133). Procedure-related mortality in the series was 1.7%. Mortality was 10-fold greater in group 1 (2.3% versus 0.2%, P < 0.0032). The incidence of small bowel obstruction, incisional hernia, and pulmonary embolism was similar in the two groups. Excess weight loss was significantly greater in group 2 (68% versus 62%, P < 0.001) at 1 year. Resolution of group 1 co-morbidities was great, including hypertension in 62%, diabetes in 75%, venous stasis disease in 96%, and pseudotumor cerebri in 98%. CONCLUSION: Outcomes analysis of obesity surgery requires risk stratification. The very low mortality rates in published studies are likely explained by surgical treatment of low-risk patients with minor co-morbidities, such as those seen in group 2. However, despite the increased perioperative risk, the group 1 patients (with major co-morbidities) demonstrated dramatic resolution of their co-morbid conditions, justifying the decision to go forward with surgery. The data support a radical change in treatment philosophy in which morbidly obese individuals should be offered bariatric surgery before major co-morbid conditions develop as a strategy to decrease the operative risk.     

Involuting solitary cutaneous infantile myofibroma and thrombocytopaenia: a previously unreported clinical association.

Solitary and multicentric myofibromas are rare fibrous tumours with marked predilection for infants and young children. Presentation is mainly before the age of 2 and lesions are often congenital. Behaviour is usually benign, but mortality has been described in lesions with visceral involvement. We report a unique case of congenital solitary cutaneous infantile myofibroma in a neonate associated with self-limiting thrombocytopaenia. It is important to distinguish accurately these lesions from benign vascular tumours like haemangiomas, locally aggressive vascular tumours like Kaposiform haemangioendotheliomas, which are often associated with Kasabach-Merritt phenomenon and also with malignant soft tissue tumours of infancy.     

Is stroke mortality on the decline in England?

This paper challenges the assumption that mortality from stroke will remain constant or decline over the next few decades. A decline in stroke mortality could be brought about by changes in factors acting close to the time of death (period effect) or by risk factors determined by the generation into which a person is born (cohort effect). Age-specific death rates for stroke (1931-1985) in England and Wales were analyzed to estimate the influence of these different effects. There were significant effects for age, period, and cohort on mortality from stroke with significantly different age and period effects in each sex. The effect of age was linear, with an increasing mortality with age in both sexes. Cohort analysis demonstrated a deceleration away from the previous trend in the mortality rates associated with birth cohorts born after 1880, followed by an acceleration in the trend of mortality rates in cohorts born after 1910. These relative increases in risk for cohorts born after 1910 were offset by a deceleration in mortality associated with periods from around 1951-1954. Since cohort effects are likely to be associated with a lifetime increase in risk of stroke mortality, it is difficult to predict the extent of any long-term fall in stroke incidence.