Thorax PostScript

Inclusion of latent tuberculosis infection as a separate entity into the international classification of diseases

2013-05-08T01:11:02-07:00

The 11th revision of the International Classification of Diseases (ICD-11) proposed by the WHO is currently in the consultation phase. In common with previous versions of the ICD this revised version does not contain a code for latent tuberculosis infection (LTBI), contrasting with the inclusion of a large number of codes for various manifestations of active tuberculosis (TB). Inclusion of a separate code for LTBI into ICD-11 is critically important for epidemiological, clinical and research purposes. On behalf of the Paediatric Tuberculosis Network European Trialsgroup, we encourage colleagues worldwide who are caring for TB patients or are involved in TB research to join us in supporting the case for a long overdue ICD code for LTBI.

Effect of CPAP on the metabolic syndrome: a randomised sham-controlled study

Hoyos, C., Sullivan, D., Liu, P. — 2013-05-08T01:11:02-07:00

A recently published editorial1 concluded that severity of disease, Continuous Positive Airway Pressure (CPAP) compliance and comorbidities might explain discrepancies between a randomised sham-controlled crossover study2 which showed that CPAP reversed metabolic syndrome (metS) and reduced weight, body mass index (BMI) and visceral abdominal fat and our findings from a randomised sham-controlled parallel-group study.3 Whether CPAP might be a novel method to reverse metS in those with Obstructive Sleep Apnea (OSA) is an intriguing possibility, since diagnosing and treating metS is important.1 We omitted to examine the effect of CPAP on metS in our population, a typical OSA cohort with treated long-standing metabolic comorbidites and less than ideal CPAP usage.1 To rectify this, we retrospectively assayed stored blood for lipids and abstracted information regarding hypertension, hyperlipidaemia and its treatment to diagnose metS.

The study design and baseline characteristics have...

Explaining differential effects of tiotropium on mortality in COPD

Lipworth, B. J., Short, P. M. — 2013-05-08T01:11:02-07:00

The editorial by Jenkins and Beasley1 makes a speculative recommendation that tiotropium Respimat should not be prescribed in the treatment of chronic obstructive pulmonary disease (COPD), being primarily based on meta-analysis where mortality was not the primary end point. The meta-analysis by Singh et al2 reported that treating 124 patients per annum with tiotropium Respimat 5 ug resulted in one additional death, although the associated 95% CI of 52 to 5682 clearly indicates that the data are not particularly robust. In considering the risk-benefit ratio of tiotropium one has to consider the seed and the soil, in terms of the degree of systemic exposure and the predisposing cardiovascular status. There is a lack of biological plausibility for the apparent disconnect between the apparent increased mortality with tiotropium Respimat on the one hand, but reduced mortality with the Handihaler on the other. Such an opposite effect...

Authors' reply to 'Explaining differential effects of tiotropium on mortality in COPD'

Jenkins, C., Beasley, R. — 2013-05-08T01:11:02-07:00

We thank Dr Lipworth1 for his response to our editorial,2 which we emphasise related to the safety of tiotropium by Respimat, not by Handihaler. We agree that UPLIFT provides very reassuring data regarding the safety of tiotropium administered by the Handihaler device in a chronic obstructive pulmonary disease (COPD) population from which people with significant diseases other than COPD, which could compromise participation or put the patient at risk, were excluded. Patients with a range of commonly encountered comorbidities, including myocardial infarction in the recent 6 months, unstable arrhythmia or hospitalisation for heart failure in the recent 12 months, or need for oxygen therapy >12 h/day, and moderate renal impairment were not eligible for UPLIFT, thereby limiting the generalisability of the findings. We also agree that a real-life analysis, such as undertaken using the Tayside data, confirming the mortality reduction on tiotropium is reassuring, although based on data...

Benzodiazepines and pneumonia or aspiration pneumonitis

Campbell-Taylor, I. — 2013-05-08T01:11:02-07:00

Dr Obiora et al1 have presented some interesting data. One could quibble about the validity of the nested case-control model, but this issue is important mainly in identifying the fact that the patients were not individually assessed, nor were their particular variables, apart from the ones of interest, benzodiazepines and pneumonia, taken into consideration. Part of the randomness was accounted for by the use of conditional logistic regression but, as frequently happens, the authors appear not to have differentiated between pneumonitis and pneumonia, not surprisingly as they were dependent on diagnoses given by other physicians. These two terms are so frequently used as synonyms that it appears that few remember that they are very different entities.2 The authors mention the greater use of benzodiazepines in the elderly, and this is one group of greatest interest.3

Individuals at an advanced age, with diseases such...

The impact of benzodiazepines on occurrence of pneumonia and mortality from pneumonia: a nested case-control and survival analysis in a population-based cohort

Iqbal, U., Syed-Abdul, S., Nguyen, P. A., Jian, W.-S., Li, Y.-C. — 2013-05-08T01:11:02-07:00

The use of benzodiazepines is not associated with community-acquired pneumonia

We read with interest the recent study done by Obiora et al1 about the incidence and mortality with pneumonia for benzodiazepine users verses non-benzodiazepine users. We were interested to see whether these results would be generalisable to the Taiwanese population, therefore, we used the National Health Insurance Database of 22 million (2002) population in order to investigate the association of benzodiazepines and community-acquired pneumonia (CAP). We selected window size of 1, 2 and 3 months to compute odds ratios of the diagnosis of pneumonia and presence of benzodiazepine prescription filling in all age and sex groups. We took patients having CAP identified through ICD-9-CM (480–486) codes (International Classification of Diseases, Ninth Revision, and Clinical Modification) and identified medications from their prescription using ATC (Anatomical Therapeutic Chemical) drug classification codes (N05BA01, N05BA02, N05BA06) system for benzodiazepines.

However, we...

Author's response

Sanders, R. D. — 2013-05-08T01:11:02-07:00

We would like to thank Drs Campbell-Taylor1 and Iqbal et al2 for their letters of interest regarding our paper.3 Nonetheless, we are unclear as to the nature of Dr Campbell-Taylor's ‘quibble’ with our methodology. In contrast to the assertion that we did not take confounders into account, we actually adjusted for comorbidities, previous pneumonia, smoking status and alcohol intake as well as age and social deprivation. The concern over whether pneumonitis and pneumonia can be differentiated from our data is more valid and we agree that there may be some errors in diagnosis and/or coding. However, these errors are unlikely to bias the results, and the mortality data indicate significant harm; therefore, ‘quibbles’ over the diagnosis do not negate the potential impact on health. It is certainly possible that benzodiazepines increase the risk of aspiration and we are grateful to Dr Campbell-Taylor for...