Showing papers by "Rolv T. Lie published in 1995"

Reliability of ultrasound in the early diagnosis of developmental dysplasia of the hip.

Abstract: The purpose of this study was to determine inter-and intra-observer agreement in assessing hip morphology and stability by ultrasound. Three groups of infants, of 206, 74 and 78 newborns respectively, were examined. Morphology was classified into four categories (normal, immature, minor dysplastic and major dysplastic) according to subjective assessment, objective measurement (of the acetabular inclination angle α) or a combination of the two. Inter- and intra-observer agreement was determined for reading of recorded ultrasound scans, and for examination (recording plus reading of the scans). Hip stability was subjectively classified as stable, unstable, dislocatable or disclocated, and inter-observer agreement was determined. There was a high degree of agreement for morphological classification based on repeated readings of recorded scans by the same observer (206 infants, κ=0.7 and 0.8 for the two observers, respectively) while the degree of agreement between observers was moderate (κ=0.5). The agreement between observers for repeated readings and recordings was moderate when based on a subjective classification (κ=0.5). Adding the α angle did not improve agreement. There was a moderate inter-observer agreement in determining hip stability (70 infants, κ=0.4). The authors concluded that a high degree of inter-and intra-observer agreement in classifying hip morphology may be obtained for the reading of recorded ultrasound scans. Inter- and intra-observer agreement in producing the scans is poorer than for reading. To obtain a high degree of inter-observer agreement in assessing hip morphology and stability in the newborn, substantial training, attention to details in the technique, and evaluation of results are necessary.

A Population-Based Study of the Risk of Recurrence of Birth Defects

Abstract: Background Certain birth defects are known to recur in families, but most estimates of the risk of recurrence have come from clinic-based studies. In this study we estimated the risk of recurrent birth defects using a population-based registry. Methods The study was based on the records of the first and second infants delivered by 371,933 women from 1967 through 1989. The records are maintained by the Medical Birth Registry of Norway. For the 9192 women whose first infant had a birth defect, we determined the relative risk of similar and dissimilar defects in the second infant. The reference population was women whose first infant had no defect. Results Among first infants, 2.5 percent had a birth defect. The mothers of affected first infants were 2.4 times as likely as other women to have second infants with any registered defect. This increased risk was due primarily to an increased (7.6 times higher) risk of the same defect in the second infant as in the first (95 percent confidence interval, 6.5 to 8....

Birth Defects Registered by Double Sampling: A Bayesian Approach Incorporating Covariates and Model Uncertainty

Abstract: SUMMARY In double-sampling schemes, a large sample is classified by using one method, and a subsample is also classified with a supplementary method. In the application discussed here, we are attempting to identify infants in Norway born with Down's syndrome by using both a national birth registry and a regional registry. Usual methods for analysing such data assume that one classification method is perfect, which is not the case here. We develop a Bayesian approach that allows for error in both registries, includes covariates (here, the age of the mother) and explicitly accounts for our lack of knowledge about the complexity of the relationships between the variables considered. Markov chain Monte Carlo methods are used to approximate the posterior. In the data considered here, the error rates of the two registries appear to be substantial. Despite a strong relationship between maternal age and risk of Down's syndrome, the inclusion of the maternal age covariate does not substantially change the overall estimates.

Cost-effectiveness of Alternative Screening Strategies for Developmental Dysplasia of the Hip

Abstract: Objective: To compare the cost-effectiveness of adding either a general or a selective ultrasound screening program to the routine clinical examination for developmental dysplasia of the hip (DDH) with use of the data from a large, randomized study of 11925 newborns. Methods: Our previous study comparing the clinical outcomes of three strategies for screening infants for DDH suggested (but results were not statistically significant) that general ultrasound screening resulted in fewer children requiring hospitalization and surgery for DDH than did a strategy based on ultrasound screening of the 11.8% of infants considered to be at increased risk of DDH or one with no ultrasound screening. General ultrasound screening led to early splinting of 3.4% of the newborns compared with 2.0% for the selectively screened group and 1.8% for the group not receiving ultrasound screening. Using these data, we decided on sequences and intervals of diagnostic and therapeutic actions considered to be sufficient for each regimen. We applied estimates of the costs of screening, treatment of DDH discovered early and late, and follow-up examinations to arrive at total program costs for each strategy. Results: Total program costs were similar for each of the three screening strategies (costs varied by Conclusions: Application of costs from other centers to our data regarding frequency of clinical outcomes may yield different comparative program costs. If the findings of our clinical study can be generalized to other centers, a strategy of screening all girls and boys with risk factors for DDH may be the most cost-effective approach. (Arch Pediatr Adolesc Med. 1995;149:643-648)

Incidence of perforated ulcer in western Norway, 1935-1990: cohort- or period-dependent time trends?

Abstract: Previous reports have shown that peptic ulcer mortality follows birth cohorts. To the authors' knowledge, temporal variation in ulcer incidence has not been studied. Therefore, they present incidence data for a defined area of western Norway where 1,312 patients born between 1845 and 1975 were treated for ulcer perforation between 1935 and 1990. A rise and subsequent fall in incidence was observed in successive birth cohorts for both sexes, with the highest incidence observed for males born between 1900 and 1919 and females born between 1920 and 1929. Age-period-cohort analyses based on Poisson regression techniques were adapted to provide a statistical tool for testing specific cohort and period effects. Age-cohort models without period effects explained the variations in incidence for both sexes and all ulcer locations, suggesting cohort-dependent etiology. A cohort pattern in prevalence of smoking partly explained the cohort pattern in perforation risks for both sexes. No period effects were seen that could be attributed to the increase in the sale of non-steroidal anti-inflammatory drugs, to the introduction of antibiotics around 1950, or to World War II. Susceptibility to ulcer perforation seems to follow birth cohorts, and major etiologic factors should be sought in prenatal life, in childhood, or in life-style patterns that follow birth cohorts.

The Effect of Ultrasound Screening on Late Developmental Dysplasia of the Hip

Abstract: Hernandez and Hensinger 1 infer that our study 2,3 shows no effect of ultrasound screening on the prevalence of late subluxated or dislocated developmental dysplasia of the hip (DDH). Our study did not exclude the possibility of no effect ( P =.11), but our data are also compatible with a significant effect of ultrasound screening. The risk for late DDH among infants undergoing ultrasound screening was 4.6 times less than the risk among infants undergoing only clinical screening (relative risk, 4.6; 95% confidence interval, 0.5-217). 2,3 Our study represents to the best of our knowledge the best attempt so far to estimate the effect of ultrasound screening on late See also pages 641 and 643 prevalence, based on a random allocation of newborns into ultrasound and reference groups. Other studies have reported a reduced prevalence of late DDH after introduction of ultrasound screening, using historical reference groups. 4,5 Estimates of the