The NICE (2006) guidelines for tuberculosis (TB) were finally published in March this year to coincide with World TB Day. Previously, those involved in the management of TB consulted the British Thoracic Society's (BTS) code of practice (BTS, 2000), which comprehensively covered the most commonly encountered TB scenarios, explained about notification and public health law and provided guidance about contact tracing procedures and the screening of new immigrants to the UK. Recommendations for the treatment of TB were available in an earlier BTS publication (BTS, 1998).
A number of developments since the BTS guidelines were published have highlighted their need for updating. For example, there has been a continued rise in the number of new cases of TB, particularly in inner cities, and an increase in instances of resistance to isoniazid, one of the drugs used to treat the condition.
Recently, changes to the supply of tuberculin for skin testing have been made, requiring a national switch from Heaf testing to the Mantoux system. In addition, the gamma interferon assay, a blood test that can detect latent TB infection and which is more specific to TB than the tuberculin skin test (TST), has become available, and guidance was required for its use.
The NICE guidelines aim to address clinical diagnosis and the management of tuberculosis as well as its prevention and control (Box 1). There are three different versions of the guidelines:
- The quick reference guide, which is 23 pages long and has colour-coded boxes and algorithms to help find information easily;
- The medium-size guideline of 66 pages, giving more detail;
- The full guideline of 215 pages, which cites all the evidence and reasoning behind the recommendations.
A supplementary document, the implementation guide, aims to help the various organisations responsible for planning and delivering care to execute its recommendations.
The quick reference guide contains a skeleton version of the guidelines and is useful mainly for the algorithms that can be worked through. Anyone looking for more detailed information would need to check one of the other versions, but even the 66-page one may not contain everything required.
The full guideline is so long that it would be impractical to try printing it from the NICE website, but it does contain some vital points that are not included in the shorter versions; for example, the issue of notification.
TB is a notifiable disease but notification is not always carried out in a timely fashion and the surveillance forms are not always adequately completed. This can lead to delays in screening contacts, with potentially serious consequences; it also causes unnecessary work for TB nurses, who have to collect missing information to complete the form correctly. It is therefore surprising that there is no mention of this in the two shorter versions and no real emphasis on the legal requirement to notify all cases of TB.
Many of the recommendations made in the BTS guidelines have been endorsed by the NICE guidelines, but there are also significant changes, particularly regarding prevention and control. This is partly due to the change in the TST and the use of the gamma interferon test, but it also represents a drive to detect and treat latent TB infection and thereby reduce the number of cases of TB.
The shift now to an emphasis on prevention and control will require a major reorganisation of screening services, with many more patients having a TST when previously they had chest X-rays. Most TB services will have to run an additional clinic every week, as Mantoux tests must be read between 48 and 72 hours after they have been given. If the guidance is followed, many more patients will need to attend these follow-up clinics.
If more people are having skin tests, latent TB will be identified, and these patients will need to be offered chemoprophylaxis to prevent TB. This is in itself a good idea but will again have a major impact on the workload of TB nurses, who will have to follow up patients to ensure that they complete a full course of treatment, which lasts for up to six months.
The NICE guideline does agree with the BTS recommendation that one full-time nurse is required for 50 notifications, and suggests one for every 40 notifications in London, but it is possible to question why urban areas such as Manchester or Birmingham do not need this level of service.
The emphasis of the guideline on tackling latent TB infection is reflected in the recommendations for occupational health screening of new NHS employees, and the algorithm has a section for new entrants. The recruitment of NHS staff from countries with a high incidence of TB is not uncommon, and these individuals are therefore at more risk of developing TB.
Unfortunately, many healthcare workers notified as having TB are employed outside the NHS by private companies and agencies and may not have had adequate occupational health screening. However, NICE says that it cannot dictate the type and extent of screening that should be adopted by these companies.
Despite the enormous content of the full guideline, it raises many questions and leaves many others unanswered. For example, although the four-drug treatment regime is advocated for patients, should we assume that we do not have to give them the fourth drug, ethambutol, if we already know the sensitivities at the outset, as often happens, particularly with non-respiratory TB?
As many microbiology laboratories use liquid culture medium (recommended in the guidelines), we often know sensitivities before completion of the two-month initial phase of treatment. Can we then stop ethambutol if the results indicate that the organism is fully sensitive to the other three drugs?
Many complicated issues are simply not addressed in the guidelines, such as TB in pregnancy, adverse drug reactions in those being treated for active TB or even recommendations for carrying out liver function testing.
Although advice is given about incentives to encourage patients to adhere to their treatment, there are no suggestions about options to manage those who repeatedly deviate from their treatment course, despite every incentive and concession being offered to them.
The NICE guidelines broadly echo the main features of the BTS guidelines and update its recommendations for screening and diagnosing latent TB infection, but as far as being user-friendly is concerned, they cannot compete with the original BTS ones. We will, of course, get used to it, particularly after completing all the NICE compliance questionnaires and audits that inevitably will follow!