Correction to: Trend estimation for complex survey designs of water chemistry indicators from Sierra Nevada Lakes.

The original version of this article contained a misaligned equation. The following equation replaces the online printed on the 5th page of the article.

Trend estimation for complex survey designs of water chemistry indicators from Sierra Nevada Lakes.

Surveys for long-term monitoring programs managing natural resources often incorporate sampling design complexity. However, design weights are often ignored in trend models of data from complex sampling designs. Generalized random tessellation stratified samples of a simulated population of lakes are selected with various levels of survey design complexity, and three trend approaches are compared. We compare an unweighted trend model, linear regression models of the trend in design-based estimates of annual status, and a probability-weighted iterative generalized least squares (PWIGLS) approach with a linearization variance. The bias and confidence interval coverage of the trend estimate and the size and power of the trend test are used to evaluate weighted and unweighted approaches. We find that the unweighted approach often outperforms the other trend approaches by providing high power for trend detection and nominal confidence interval coverage of the true trend regression parameter. We also find that variance composition and revisit design structure affect the performance of the PWIGLS estimator. When a subpopulation exhibiting an extreme trend is sampled disproportionately to its occurrence in the population, the unweighted approach may produce biased estimates of trend with poor confidence interval coverage. We recommend considering variance composition and potential subpopulation trends when selecting sampling designs and trend analysis approaches.

Sports concussion in the child and adolescent athlete.

Sports concussions are common among children and adolescents, and recent evidence suggests that concussions are more serious injuries than previously thought. Young athletes appear to recover from concussion more slowly than older athletes. Recovery is prolonged if these athletes return to play or school prematurely, and reinjury increases their risk of more serious sequelae. These newer data on concussions have raised our appreciation of this injury and have informed the development of more conservative treatment guidelines for the child and adolescent athlete. The purpose of this JAMS article is to review the new evidence and the most recent management guidelines regarding sports concussion in the young athlete.

Childhood hemolytic uremic syndrome is associated with adolescent-onset diabetes mellitus.

Extra-renal manifestations of the hemolytic uremic syndrome in children are well described. Pancreatic involvement may manifest as transient hyperglycemia and permanent diabetes mellitus. Two previous case reports demonstrate short periods of "remission" between initial hyperglycemia and the development of permanent diabetes mellitus. We report an unusual case of a two-year-old Caucasian boy whose HUS-associated hyperglycemia resolved shortly after the acute phase of his illness only to recur as permanent diabetes mellitus at puberty. To our knowledge no other case is reported that demonstrates such a long interval between initial presentation and the development of permanent diabetes mellitus.

Procreative experiences and orientations toward paternity held by incarcerated adolescent males.

PURPOSE: To describe the procreative experiences and the attitudes related to paternity held by a sample of incarcerated adolescent males. METHODS: All adolescent males who were admitted to a long-term correctional facility between July 1994 and October 1994 were asked to participate in a confidential, face-to-face interview. RESULTS: One hundred twenty-five incarcerated adolescents agreed to participate in the study. Over one-quarter (25.6%) of the respondents reported having ever gotten a girl pregnant; 40.6% of fathers reported having caused more than one pregnancy. A majority of respondents believed that fathering a child would be desirable, that they would be capable of being a father to a child, and that they could be responsible for the baby and mother. Fathers were more likely than nonfathers and black respondents were more likely than white respondents to report that they, their parents, and their friends would be pleased were they to get girls pregnant. Black respondents were more likely than white respondents to believe that they could be a good father to a child. CONCLUSIONS: The general perceptions that fathering a child as a teenager is desirable and that they could be good fathers to their children will make the prevention of pregnancy and parenting difficult in this population. Incarcerated adolescents should be educated about parenting prevention using interventions that take into consideration their attitudes and perceptions of teenage parenting.

Risk for gonococcal and chlamydial cervicitis in adolescent females: incidence and recurrence in a prospective cohort study.

PURPOSE: This study attempted to determine the incidence and risk for gonococcal and chlamydial cervicitis among sexually active urban adolescent females. METHODS: The study design is a prospective cohort study. A cohort of 216 sexually active females were followed with repeat sexually transmitted diseases screening for 12-24 months. Subjects positive on any retest (FU) were compared with those who remained negative on all FU. Subjects were interviewed for history and screened for endocervical gonococcal and chlamydial infection. RESULTS: The number of visits per patient ranged from 2 to 9 (median, 3). The initial Chlamydia trachomatis and Neisseria gonorrhoeae rates were 23.2 and 11.6%, respectively. The cumulative FU positive rates were 20.8% for C. trachomatis and 17.1% for N. gonorrhoeae. Although the initial gonococcal infection was a significant risk for a subsequent infection by C. trachomatis (p = .05) and N. gonorrhoeae (p = .001), the initial C. trachomatis status was not predictive of subsequent infections. The number of partners was not predictive of subsequent infections with either. In the entire study period, 86 patients had at least one episode of C. trachomatis and N. gonorrhoeae infection was confirmed in 52; 20 patients had recurrent cervicitis. During the study, 101 episodes of C. trachomatis and 68 episodes of N. gonorrhoeae infections were identified. Those with recurrent cervicitis (9.3%) were responsible for 33% of all cervicitis episodes identified during the study. CONCLUSIONS: Adolescents in our study were at high risk for cervicitis, particularly as a result of C. trachomatis. Risk for subsequent C. trachomatis cervicitis was the same among initially positive and negative groups. Our data underscore the importance of repeat screening for sexually transmitted infections and treatment of contacts of adolescent females.

Intraoperative echocardiography during congenital heart operations: experience from 1,000 cases.

BACKGROUND: This article provides an overview of the application of intraoperative echocardiography during repair of congenital heart defects based on our experience with 1,000 patients. METHODS: The patients in this study all underwent repair of a congenital heart defect between 1987 and 1994 at Duke University Medical Center. Echocardiography was performed on all patients in the operating room both before and after repair using epicardial or transesophageal imaging (or both). Hospital costs and outcome data were obtained for all patients. RESULTS: Overall, 44 patients (4.4%) underwent intraoperative revision of their repair based on echocardiographic findings. There was an initial learning phase during which 8.5% of repairs needed to be revised. With experience, the number of revisions fell to as low as 3% to 4%, but need for revision continued to occur throughout the series. Thirty-nine patients (88.6%) had a successful revision. It was not possible for the surgeon to predict the need for a revision based on his confidence in the repair: in 2.6% of patients thought by the surgeon to have a good repair, intraoperative echocardiography revealed the need for operative revision. The average cost for patients who return to the operating room during their hospitalization for revision of a repair is significantly greater than for those whose repairs are revised before they leave the operating room ($94,180.28 +/- $33,881.63 versus $21,415.79 +/- $8,215.74). There were no significant complication attributable to intraoperative echocardiography. CONCLUSIONS: In an era where complete repair of congenital heart defects is emphasized, intraoperative echocardiography provides information that can guide successful operative revision so that babies leave the operating room with optimal results.