Journal Club

May 1, 2001

JOURNAL CLUB

 

JOURNAL CLUB

Jump to:Choose article section... Studies should calm MMR vaccine fears Blood pressure control: Another breast milk plus? TA thermometer the next best thing Also of note CLINICAL TIP Mineral oil: Another flavor

Commentaries By Michael G. Burke, MD

Studies should calm MMR vaccine fears

Three new studies undercut recent public concern that measles-mumps-rubella (MMR) vaccination is associated with autism, Guillain-Barre syndrome (GBS), and inflammatory bowel disease (IBD).

To examine the purported association between MMR vaccination and autism, investigators began by analyzing retrospectively MMR immunization coverage rates among children born from 1980 to 1994 who were enrolled in California kindergartens. They determined the age at which the children first received MMR immunization and, for the same period, examined the autism caseload of the California Department of Developmental Services regional service center system, which functions as a service hub for all of the state's counties. Autistic disorder cases increased from 44 cases per 100,000 live births in 1980 to 208 per 100,000 live births in 1994, a 373% increase. Increases in early childhood MMR immunization coverage during the same period were much smaller, rising only 14%. These data suggest that no association exists between MMR immunization and an increase in autism.

In another retrospective study, investigators assessed the postulated causal association between MMR vaccination and GBS by examining the records of patients hospitalized for treatment of GBS in Finland between November 1982 and December 1986. Of 189 patients hospitalized for GBS, 20 of 24 representing the target population for MMR vaccination had been vaccinated. None of the 20 had GBS symptoms within six weeks of the vaccination, the period designated as suggestive of a causal association between MMR vaccination and GBS.

Finally, a case-control study in four large health maintenance organizations showed that vaccination with MMR or another measles-containing vaccine did not increase the risk of IBD (Crohn's disease or ulcerative colitis). The study group included 142 patients with IBD, of whom 94 (66%) had been vaccinated with MMR, 38 (27%) with another measles-containing vaccine, and 10 (7%) who had never been vaccinated with either. Among the 432 controls, 300 (69%) had been vaccinated with MMR, 109 (25%) with another measles-containing vaccine, and 23 (5%) had neither vaccination. Individuals with Crohn's disease or ulcerative colitis were no more likely than controls ever to have been vaccinated (Dales L et al: JAMA 2001;285:1183; Patja A et al: J Pediatr 2001;138:50; Davis RL et al: Arch Pediatr Adolesc Med 2001;55:54).

Commentary: MMR and other vaccines have really been handed a bad rap, with groups claiming that these vaccines cause a lengthy list of complications. Some claims have been widely broadcast in the press and across the Internet without reasonable epidemiologic evaluation. Meanwhile, you are left in your office defending immunization practices. For a good source of information about what is and is not true about vaccine safety, check out this Web site: www.vaccinesafety.edu .

Blood pressure control: Another breast milk plus?

A recent trial supports the hypothesis that premature infants who consume human milk may tend to have lower blood pressure later in life than peers fed formula in infancy. Beginning in 1982, investigators in the United Kingdom conducted two parallel randomized trials in 926 babies born prematurely. One trial compared the effects of banked breast milk with nutrient-enriched preterm formula during a one-month period. The other compared a standard term formula with the nutrient-enriched preterm formula. In a follow-up in 216 of the babies when they reached 13 to 16 years of age, investigators measured four key cardiovascular parameters, including blood pressure. Mean arterial pressure and diastolic blood pressure were significantly lower in children assigned banked breast milk than in those assigned preterm formula. The differences in systolic blood pressure were insignificant. Diastolic, systolic, and mean arterial blood pressures did not differ significantly between children fed term formula and those fed preterm formula (Singhal A et al: Lancet 2001;357:413).

Commentary: The differences in blood pressure are statistically significant but are small. Would they make a clinical difference? The authors think so. They contend that, on a population basis, these changes would have a large effect, perhaps reducing prevalence of hypertension by 17% and heart disease by 6%. Yet another endorsement for breastfeeding infants.

TA thermometer the next best thing

Will infants tolerate a new noninvasive temporal artery (TA) thermometer as well as they do the tympanic technique? Does the TA thermometer give results that closely agree with rectal temperature? To answer these questions, investigators measured the temperature of 304 infants (to 1 year of age) who were brought to an emergency department. They used TA and tympanic thermometers and compared their accuracy, sensitivity, and specificity with that of rectal thermometers (the standard). The TA thermometer was significantly more accurate than the tympanic thermometer for predicting rectal temperature in infants. In addition, the TA thermometer was significantly more sensitive than the tympanic thermometer, although the two thermometers did not differ significantly in specificity. Infants seemed to tolerate the TA thermometer better than the rectal thermometer. The authors concluded that rectal thermometry should still be the preferred method of measuring temperature in infants. If the rectal thermometer is not used, the TA thermometer appears to be a better alternative than the tympanic thermometer (Greenes DS et al: Arch Pediatr Adolesc Med 2001;155:376).

Commentary: The passing of tympanic thermometers would be no great loss, as far as I am concerned. I have always had the uneasy feeling that these devices' results are questionable, especially in infants.

Editor's note: For more on measuring fever (and managing it), see "Fever: Measuring and managing a sizzling symptom."

Also of note

Is it child abuse? Do a skeletal survey. A new study confirms that the skeletal survey is an important radiologic tool for the clinical evaluation of suspected child abuse. Examination of the medical records of 96 children with a diagnosis of alleged physical abuse who had a skeletal survey showed that those who were most likely to have an occult fracture were younger than 1 year or had an intracranial injury or an obvious skeletal fracture. The child with a burn injury was least likely to have a clinically unsuspected fracture (Belfer RA et al: Am J Emerg Med 2001;19:122).

Drop in air pollution reduces asthma exacerbations. The 1996 Summer Olympic Games in Atlanta, Ga., offered investigators a unique opportunity to study the relationship between automobile traffic, air quality, and asthma morbidity. Traffic density was much lighter than usual in the city during this period because of a successful public transportation strategy to transport large numbers of people efficiently. This resulted in a significant reduction in peak daily ozone concentrations as well as peak weekday morning traffic counts. Investigators compared the number of hospitalizations, emergency department visits, and urgent care visits for asthma in children 1 to 16 years old during the 17 days of the games with two four-week periods before and after them. Four different sources of patient data indicated a reduction in acute asthma events during the Olympic Games. These included a statistically significant 41.6% reduction in Medicaid emergency visits and hospitalizations for asthma (Friedman MS et al: JAMA 2001; 285:897).

DR. BURKE, Section Editor for Journal Club, is Chairman of the Department of Pediatrics at Saint Agnes Hospital, Baltimore. He is a Contributing Editor for Contemporary Pediatrics.

CLINICAL TIP

Mineral oil: Another flavor

To resolve constipation in a young child, I find that mixing mineral oil in chocolate milk makes an effective preparation. It seems to precipitate little and goes down well. I use about an ounce of milk or just enough to disguise the taste and texture of the mineral oil. The mixture does leave sippy cups more difficult to clean than usual, however.

Matthew E. Abrams, MD
Indianapolis, Ind.

Do you have a Clinical Tip to share with colleagues? Let us know; we'll pay $50 for each item accepted for publication. Tips sent by mail should be addressed to Molly Frederick, Clinical Tips Editor, Contemporary Pediatrics, 5 Paragon Drive, Montvale, NJ 07645-1742. If you submit by e-mail (Molly.Frederick@medec.com), please include your mailing address.

 

Journal Club. Contemporary Pediatrics 2001;5:122.