This week in the BMJ

Volume 325, Number 7377, Issue of 14 Dec 2002

Self help intervention during antenatal care fails to cut smoking
Topical $beta$ blockers may cause new airways obstruction
Worldwide gastroschisis epidemic
Early CT improves diagnosis in abdominal pain
Emergency contraception is not an easy choice
Papers with competing interests are less credible
Introduction of NHS Direct did not cause under-reporting of flu

Self help intervention during antenatal care fails to cut smoking

A low cost, self help intervention to stop smoking in pregnancy was acceptable to midwives and pregnant women, but was ineffectivewhen implemented during routine antenatal care. A cluster randomisedtrial by Moore and colleagues (p 1383) randomised midwives eitherto continue to provide pregnant smokers with normal care or additionallyto introduce a series of self help booklets to encourage smokingcessation and prevent relapse. Cotinine validated cessation rateswere similar in both trial arms, but substantially lower thanthe self reported rates on which current smoking policy is based.

(Credit: SIPA/REX)

Topical $beta$ blockers may cause new airways obstruction

In elderly patients without respiratory disease, topical $beta$ blockers used for glaucoma may induce new cases of airway obstructionrequiring treatment. Topical $beta$ blockers are known to exacerbateexisting airways disease, but Kirwan et al (p 1396) used the Mediplusdatabase to compare patients with no diagnosis of airways obstructionwho were given topical $beta$ blockers for the first time with controlsnot given $beta$ blockers. Among 2645 exposed patients the adjustedhazard ratio for developing airways obstruction at 12 months afterthe start of treatment was 2.29 (1.71 to 3.07) $---$ a number neededto harm of 55patients.

Worldwide gastroschisis epidemic

The prevalence of gastroschisis $---$ a congenital malformation of the abdominal wall $---$ at birth has increased worldwide. Di Tannaand colleagues (p 1389) found a substantial rise $---$ from 0.29 to1.66 per 10 000 population. The authors investigated the prevalenceof gastroschisis among 37 million births in registries from 22countries worldwide from 1974 to1998.

Early CT improves diagnosis in abdominal pain

Computed tomography of the abdominopelvic region undertaken in patients with acute abdominal pain soon after admission mayreduce inpatient mortality and length of hospital stay. Ng andcolleagues (p 1387) randomised 120 patients with acute abdominalpain of unknown cause to early computed tomography or standardpractice. The falls in inpatient mortality and length of staywere not statistically significant, but early computed tomographymissed fewer serious diagnoses than other standard investigations.

Emergency contraception is not an easy choice

Several factors influence whether young women choose to use emergency contraception. Free and colleagues (p 1393) carriedout in-depth interviews of 30 women aged 16-25. Those women whoexpressed the strongest desire to avoid pregnancy used emergencycontraception if necessary. Women who did not use emergency contraceptionfelt less vulnerable to pregnancy, had negative associations withemergency contraception and the people who used it, or found itdifficult to seek or ask for emergency contraception.

"I didn't know where I was supposed to go and if I was allowed . . . because I was young, I was like 14"

Papers with competing interests are less credible

When the authors of a research paper declare substantial competing interests, readers find it less interesting, important,relevant, valid, and believable than when the authors have nosuch interests. Chaudhry et al (p 1391) performed a randomisedtrial among 300 BMJ readers in which half were sent a short researcharticle where the (fictitious) authors were employees of a companyand held stock options. The other half received the same articlebut with authors who had no such competing interests. On all measuresthe readers who received the first version rated it lower thanthose who received thesecond.

Introduction of NHS Direct did not cause under-reporting of flu

Despite media interest, the introduction of NHS Direct had no impact on consultations for influenza-like illness and otherrespiratory infections. Chapman et al (p 1397) compared data onconsultations for respiratory diseases in the winters of 1996-7and 1999-2000, a period preceding and covering the introductionof NHS Direct. They found no basis for the claims that an influenzaepidemic had occurred in 1999-2000 but was under-reported becausepeople were contacting NHS Direct instead of their general practitioner.