Standards for total body fat and fat-free mass in infants

Data on body composition in conjunction with reference centiles are helpful in identifying the severity of growth and nutritional disorders in infancy and for evaluating the adequacy of treatment given during this important period of rapid growth. Total body fat (TBF) and fat-free mass (FFM) were estimated from total body electrical conductivity (TBEC) measurements in 423 healthy term Caucasian infants, aged 14-379 days. Cross sectional age, weight, and length related centile standards are presented for TBF and FFM. Centiles were calculated using Altman's method, based on polynomial regression and modelling of the residual variation. The TBF percentage steeply increased during the first half year of life, and slowly declined beyond this age. Various simple TBEC derived anthropometric prediction equations for TBF and FFM are available to be used in conjunction with these standards. Regression equations for the P50 and the residual SD, depending on age, weight, or length, are provided for constructing centile charts and calculating standard deviation scores.     

Follow-up of surgical correction of vascular anomalies causing tracheobronchial compression

Summary Between January 1977 and January 1990, 44 patients with symptomatic vascular rings/slings required surgical intervention at this center. Nineteen patients had double aortic arch (group I); 13 patients had vascular ring consisting of right aortic arch, anomalous origin of the left subclavian artery, and ligamentum arteriosus (group II); eight patients had innominate artery compression (group III); and four patients had pulmonary artery sling (group IV). Three patients had complex congenital heart defect and died secondary to it and are excluded from the study. Follow-up was obtained on 31 patients (76%). The follow-up period ranged from 0.4 years to 10.9 years, with a mean of 3.6 years. Seventy percent of the overall group were asymptomatic, and 30% of patients continued to have upper and lower respiratory symptoms on late follow-up. One third of patients in groups I and II, who underwent surgical repair, continue to have symptoms. Patients who have persistent symptoms should be further evaluated with PFTs, MRI, and bronchoscopy, and may benefit from aortopexy. Patients with innominate artery compression and pulmonary artery sling do well soon after surgery with relief of most of their symptoms.     

Roxatidine versus ranitidine in the treatment of duodenal ulcers: A randomized double-blind controlled multicentre study in Singapore

Roxatidine acetate, a new H₂ receptor antagonist, was compared with ranitidine in the treatment of duodenal ulcers in a double-blind multicentre study. Eighty-four patients with endoscopically proven duodenal ulcer were randomized to receive 150 mg roxatidine acetate or 300 mg ranitidine at bedtime. Repeat endoscopy was performed after 4 weeks (25–33 days) and if the ulcer had not healed, another endoscopy was performed after a further 4 weeks of treatment. Using per protocol analysis 73.6% of ulcers treated with roxatidine healed at 4 weeks compared to 72.2% of ulcers treated with ranitidine (P=NS). The healing rates at 8 weeks were 92% with roxatidine and 83.3% with ranitidine (P=NS). Using equivalence tests, the healing rate of roxatidine was found to be equivalent to that of ranitidine within a 20% region. Roxatidine users took significantly less antacids than ranitidine users (P < 0.05). There were no significant adverse effects due to roxatidine or ranitidine. Roxatidine is a safe effective drug in the treatment of duodenal ulcers with a healing rate comparable to that of ranitidine.     

Telephone health surveys: potential bias from noncompletion.

OBJECTIVES. Little is known about the effect of noncompletion on telephone surveys of health issues. This paper identifies a little-studied source of noncompletion, passive refusal, and evaluates its contribution to noncompletion bias along with two other sources: noncooperation and noncontact. Passive refusals include respondents who repeatedly request callbacks and households where interviewers repeatedly encounter an answering machine. METHODS. Measures of noncompletion (noncooperation, passive refusal, and noncontact), demographic and socioeconomic characteristics, health risk factors, and indicators of health care access and health status were collected through the Orange County Health Surveys on 4893 respondents. The surveys sampled by random-digit dialing and interviewed by computer-assisted telephone. RESULTS. Passive refusals have a substantial impact on completion rates and bias due to noncompletion. Commonly used definitions for completion rates may underestimate the bias due to noncompletion because they omit passive refusals. After we controlled for demographic and socioeconomic factors, few noncompletion biases appeared on selected health indicators. CONCLUSIONS. These results suggest improved reporting of completion rates and support a multivariate framework for studying noncompletion in telephone health surveys.