Planned missing data designs in psychological research.

The authors describe 2 efficiency (planned missing data) designs for measurement: the 3-form design and the 2-method measurement design. The 3-form design, a kind of matrix sampling, allows researchers to leverage limited resources to collect data for 33% more survey questions than can be answered by any 1 respondent. Power tables for estimating correlation effects illustrate the benefit of this design. The 2-method measurement design involves a relatively cheap, less valid measure of a construct and an expensive, more valid measure of the same construct. The cost effectiveness of this design stems from the fact that few cases have both measures, and many cases have just the cheap measure. With 3 brief simulations involving structural equation models, the authors show that compared with the same-cost complete cases design, a 2-method measurement design yields lower standard errors and a higher effective sample size for testing important study parameters. With a large cost differential between cheap and expensive measures and small effect sizes, the benefits of the design can be enormous. Strategies for using these 2 designs are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

School and community climates and civic commitments: Patterns for ethnic minority and majority students.

The developmental correlates of diffuse support for the polity and civic commitments were explored in a survey of 1,052 students (mean age = 14.96 years) from African American, Arab American, European American, and Latino American backgrounds. Results of structural equation modeling revealed that regardless of their age, gender, or ethnic background, youth were more likely to believe that America was a just society and to commit to democratic goals if they felt a sense of community connectedness, especially if they felt that their teachers practiced a democratic ethic at school. Discussion focuses on the civic purposes of education in inculcating a sense of identification with the polity in younger generations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family cohesion, family adaptability, social support, and adolescent depressive symptoms in outpatient clinic families.

The relationships among adolescent depressive symptoms and self-reported family cohesion, adaptability, satisfaction with family functioning, family structure, and social support received from family and friends were investigated in a sample of 93 families attending family therapy at an outpatient clinic. Results were in keeping with previous studies of nonclinical samples, in that family cohesion and family social support were inversely related to depression. In contrast to nonclinical samples, family characteristics were more strongly associated with depression among boys than among girls, and social support from friends did not act as a buffer against depression. The strongest predictor of depressive symptoms was adolescents' levels of satisfaction with the cohesiveness and adaptability in their families, suggesting the importance of subjective cognitive appraisal in the link between family functioning and depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of the use of statistical methods in health research

BACKGROUND: Computer use has lead to a great development of statistical methods. AIM: To assess the use of statistical methods in Chilean medical literature. METHODS: Two hundred sixty four papers appeared in Revista Médica de Chile and Revista Chilena de Pediatría between 1983 and 1993 were reviewed. RESULTS: Student's "t", Fisher's, and chi 2 test are the most frequently used statistical methods in 67% of papers. Correlation coefficients are used in 10% of papers. Multivariate methods are seldom used. CONCLUSIONS: Statistical analysis of papers published in Chilean medical journals is restricted to very few methods.     

Comparative study of the efficacy of two types of BCG vaccines administered in different doses

BACKGROUND: In 1993, WHO and UNICEF recommended the administration of 0.05 ml doses of BCG, instead of 0.1 ml, to newborns. This recommendation was adopted by the Chilean Ministry of Health, using the Mérieux vaccine. Subsequently, different Health Services detected a high percentage of children without BCG scar at the time of their growth and development control. AIM: To assess the efficacy of BCG vaccination in a double blind randomized fashion, using two vaccine types and different doses. PATIENTS AND METHODS: Newborns of two public hospitals of Santiago were randomly assigned to receive the Tokio or Mérieux BCG strains in doses of 0.05 or 0.1 ml. Ninety five to 125 days after vaccination, vaccine scar was measured and inmunogenicity was assessed using the tuberculin test. RESULTS: Six hundred newborns (150 in each group) were included in the protocol and results were assessed in 408. The percentage of children with a PPD reaction of 0 mm was 9.3, 3.7, 7.8 and 0% with the Mérieux vaccine in doses of 0.1 ml, Tokio vaccines in doses of 0.1 ml, Mérieux vaccine in doses of 0.05 ml and Tokio vaccine in doses of 0.05 ml, respectively. In the same groups the scar diameters were 6.4 +/- 3.4, 7.3 +/- 2.7, 5.6 +/- 2.8 and 7.3 +/- 2.9 mm. The observed differences for each group are significant, depending on the type of strain and dose, but favoring the Tokio type of vaccine. CONCLUSIONS: The BCG scar diameters obtained in this study are similar to those obtained in previous works in 1984 and 1986. This scar is the evidence of vaccination that nurses detect in health controls. Therefore the use of 0.1 doses for vaccination, that result in better scars and PPD response, is recommended.     

Perceived exposure to peer and adult drinking as predictors of growth in positive alcohol expectancies during adolescence.

This study investigated the effects of change in exposure to peer and adult drinking on changes in positive alcohol expectancies during adolescence. Covariance and mean structure analysis were used to model change in the predictors and in alcohol expectancies in a sample of southern California schoolchildren followed from Grades 5 to 10 (N?=?3,580). The sample was gender balanced and was predominantly White (51 %) and Hispanic (28%). Exposure to peer drinking and rate of change in exposure to peer and adult drinking were found to predict the rate of change in alcohol expectancies. These effects were particularly strong between Grades 5 and 7, suggesting the need for early intervention aimed to prevent the increase in positive alcohol expectancies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Clinical experience with an alpha glucosidase inhibitor (acarbose) in the treatment of non-insulin-dependent diabetes. Multicenter study

BACKGROUND: Acarbose, an alpha glucosidase inhibitor is a drug used in the treatment of non insulin dependent diabetes mellitus, that interferes with the intestinal absorption of monosaccharides. AIM: To study the effect of acarbose in non insulin dependent diabetic patients that had an inadequate metabolic control with diet and sulphonylureas. PATIENTS AND METHODS: Diabetic patients received acarbose, 150 mg/day during four weeks and this dose was increased to 300 mg/day during 3 months. Afterwards, patients were followed for a period of 12 weeks without acarbose. Fasting and post-prandial blood glucose and glycosilated hemoglobin were measured sequentially during the study. RESULTS: Eighty five patients were recruited for the study but 64 complied with the treatment protocol. The age of these patients was 56 +/- 8.8 years old, their diabetes duration was 7.8 +/- 8.8 years and their body mass index was 27.6 +/- 3.6 kg/m2. During acarbose treatment, glycosilated hemoglobin decreased from 8.36 +/- 1.33 to 7.71+ 1.7% (p < 0.001), fasting blood glucose decreased from 173 +/- 48 to 159 +/- 59 mg/dl (p < 0.03) and post-prandial blood glucose decreased from 254 +/- 80 to 241 +/- 80 mg/dl (NS). After discontinuing acarbose glycosilated hemoglobin and blood glucose levels returned to basal levels. Body weight and blood pressure did not change during the treatment period. Fifty nine patients had gastrointestinal symptoms (meteorism, flatulence and abdominal distention) that were mild in 59% and moderate in 39%. Episodes of hypoglycemia were not observed. CONCLUSIONS: Acarbose, associated to sulphonylureas is an effective drug to reduce blood glucose and glycosilated hemoglobin levels in patients with non insulin dependent diabetes.