view of general practitioners' skills in treating back pain syndromes. Anyone who chooses may put up a plate claiming to be a chiropractor. There are similar problems of identity for other professional groups, including physiotherapists. I understand that all members of the British Chiropractic Association have completed a three year course. This is not the case for many who call themselves chiropractors. I suggest that the association circulates a list of its members to general practitioners and other interested health professionals, as the Chartered Society of Physiotherapy does. In the long term the government will have to initiate registers of professional groups showing the qualifications and extent of training of those on the register. J C T FAIRBANK
Nuffield Orthopaedic Centre, Oxford OX3 7LD 1 Meade TW, Dwyer S, Browne W, Townsend J, Frank AO. Low back pain of mechanical origin: randomised comparison of chiropractic and hospital outpatient treatment. Br Med J 1990;300:1431-7. (2 June.)
SIR,-The study by Dr T W Meade and colleagues must have come as a shock to many doctors, perhaps less so to those who listen to their patients.' The lack of communication in the past among those who treat patients with problems of the musculoskeletal system has been unnecessary, though financial and professional competition has made it understandable. The Physical Medicine Research Foundation, founded in 1985, aims to break down such barriers of communication-study, understanding, and treatment of the musculoskeletal system will progress much faster by coordinating the efforts of all concerned including doctors, chiropractors, osteopaths, and physiotherapists. The foundation awards grants preferentially to cooperative researchers from more than one discipline and organises multidisciplinary meetings. An important international meeting, drawing doctors and others from countries as far apart as Czechoslovakia and Australia, has just been held in Vancouver. Another is planned for Oxford in 1992. R M ELLIS
not numerous. The psychological characteristics of the two treatment groups were virtually identical. Both treatment approaches included educationmore so, if anything,.for patients treated in hospital than by chiropractic. Patients for whom litigation or compensation was at issue were, we pointed out, excluded from the trial. The absence of a clear relation between the number of treatments and outcome suggests that the benefit of chiropractic may be achieved with fewer treatments. We therefore doubt Joyce Wise's conclusion that more treatments might be effective. We dealt fully with the absence of a chiropractic effect in first time patients. It would be wrong to make too much of the one centre in which hospital treatment appeared slightly more effective because none of the differences at the various follow up intervals were even marginally significant. Turning to broader issues of research and policy, we did not, as Joyce Wise states, show that open access physiotherapy is as effective as, or better than, chiropractic but we agree that the availability of open access facilities in enabling early treatment and the effectiveness of nonmanipulative methods are important topics for further study. We agree with many of her other suggestions and those of Dr Sturge and Ms Bulstrode. Increasing the number of physiotherapists with manipulation skills in the NHS, improving the general conditions under which many physiotherapy departments work, increasing the precision of defining which patients benefit from chiropractic, and increasing the effectiveness of treatment in the many patients for whom manipulation is not an option are also obvious topics for further research and, naturally, we welcome Joyce Wise's commitment to assistance
from physiotherapists. Realistically, however, these questions are unlikely to be settled for several years. In the interim we believe that the substantial long term benefit of chiropractic in patients with chronic and severe low back pain makes it necessary to consider the availability of chiropractic to NHS patients now. T W MEADE
MRC Epidemiology and Medical Care Unit, Northwick Park Hospital, Harrow HAl 3UJ A 0 FRANK
Odstock Hospital, Salisbury SP2 8BJ
Northwick Park Hospital, Harrow HAI 3UJ
I Meade TW, Dyer S, Browne W, Townsend J, Frank AO. Low back pain of mechanical origin: randomised comparison of chiropractic and hospital outpatient treatment. Br Med J
Passive smoking
1990;300:1431-7. (2 June.)
AUTHORS' REPLY,-To deal first with technical points, Mr G P Graham and colleagues give a misleading figure for recruitment to the trial. Eligibility depended on the absence of contraindications to manipulation. We pointed out that, of those so eligible, 47% entered the trial. While bias of the sort Mr Graham and colleagues refer to is a theoretical possibility, there is no evidence for it and much against it. Indeed, they acknowledge that chiropractic is effective in some patients. Mr C H Brooks's comment about interobserver variability is largely irrelevant, because both measures of straight leg raising-included, incidentally, on orthopaedic advice-were made by the same observer, who had been trained in the technique. The principles are no different from those of, for example, measuring blood pressure and using the results. It was exactly to provide objective evidence in place of the impressions on which Mr M A Edgar relies that we carried out our trial. Few will give serious consideration to his suggestion that we should have deliberately included patients who might have been harmed by manipulation. Analysis by "intention to treat" will have largely taken account of Mr C G Greenough's point about incomplete treatment courses, though these were
1650
SIR,-Mr Norman Swan suggests that a motivation for smoke free workplaces in Australia comes from a series of workers' compensation payouts to people claiming illnesses caused by passive smoking.' He cites the case of Sean Carroll, a Melbourne bus driver. Your readers should be aware that no compensation was awarded for lung cancer which was in any way due to exposure to tobacco smoke. Sean Carroll lodged a claim for compensation under the Accident Compensation Act in January 1988. Carroll's claim form described his injury as "coughing" which affected the lungs and was due to "fumes from bus, aggravate lung condition." The medical certificate in support described the injury as "chest infection due to diesel fumes." Carroll was medically examined to substantiate his claim. During this examination his lung cancer was first diagnosed. Carroll's lawyers sought to amend the injuries alleged in the claim to include lung cancer due to exposure to cigarette smoke. The arbitrator held that Carroll was forced to cease work because of the effect of bus fumes on his lungs generally but did not make any finding in respect of a connection between lung cancer and exposure to environmental tobacco smoke. The arbitrator recommended that Carroll be placed on weekly payments of compensation. The Accident Compensation Commission and the State Insurance
Office appealed against this decision. At this time Carroll's claim was amended to include an allegation that his lung cancer had been produced, aggravated, accelerated, or exacerbated by "inhalation of cigarette smoke, exhaust emissions including bus emissions and air pollution." The State Insurance Office, Carroll's employer's insurers, made a commercial decision to settle Carroll's claim. The decision was the product of an exercise in mathematics and not of any conclusions about the health effects of exposure to environmental tobacco smoke, to which Carroll may have been exposed during the course of his employment. As a result of the insurers settling out of court the media assumed and reported that Carroll had been paid damages for an illness caused by so called passive smoking. This was not the case. In fact, during the course of the hearing evidence disclosed that Carroll drove his bus in a separate compartment from the passengers. Moreover, smoking was banned on Melbourne buses in 1976, 12 years before Carroll's compensation claim. The settlement of Carroll's case meant that the Accident Compensation Tribunal was not called on to decide whether Carroll's lung cancer was in any way attributable to exposure to tobacco smoke. The position remains that no court in Australia or anywhere else in the world has determined that there is any causal connection between exposure to environmental tobacco smoke and lung disease. A A WOOD Public affairs director
Rothmans International Services, Uxbridge UB9 5BL 1 Swan N. Australia invokes workers' compensation. Br Med J
1990;300:1357. (26 May.)
Radiolucent dentures SIR,-Mr George E Murty and Dr S Fawcett warn that dentures are radiolucent.' I believed that all medical practitioners knew that such material was radiolucent and that plain radiographs are useless as a diagnostic tool. Yet there seems to be a fundamental lesson to be learnt-namely, that proper attention should always be paid to the history of swallowing a foreign object which can lodge in the oesophagus with potential damage, however bizarre the history may be. As doctors we do have the advantage over veterinary surgeons in that patients-or their relatives-can talk to us. I have always practised and taught that when in doubt the only safe procedure is oesophagoscopy. This is becoming even more important in these days of increasing medical negligence litigation. Two personal cases may be of interest. A 7 year old boy was playing "cowboys and Indians" and pretended that he had been shot in the head by an arrow. He was running around with this in his mouth when he collided with a wall and broke the arrow. His mother brought him to hospital, saying that only one end of the arrow had been found. The boy was having some difficulty in swallowing and adamantly said that the arrow "had gone down." Examination of the oropharynx showed no trauma but oesophagoscopy found 15 cm of wooden arrow with a rubber sucker at the end, which was removed from the mid-oesophagus. An 18 year old swallowed a partial denture ih similar circumstances to those recorded by Mr Murty and Dr Fawcett. He was reassured by his local accident and emergency department but seven days later was admitted with massive haematemesis. At oesophagoscopy the denture was found to be embedded in the wall of the oesophagus, which it had perforated. At subsequent thoracotomy there was a septic mediastinitis with one end of the denture perforating the thoracic aorta. The aortic wall was infected and friable and would not take sutures. Sadly, the youth died. This also raises the important issue as to whether
BMJ VOLUME 300
23 JUNE 1990
Nuffield Orthopaedic Centre, Oxford OX3 7LD 1 Meade TW, Dwyer S, Browne W, Townsend J, Frank AO. Low back pain of mechanical origin: randomised comparison of chiropractic and hospital outpatient treatment. Br Med J 1990;300:1431-7. (2 June.)
SIR,-The study by Dr T W Meade and colleagues must have come as a shock to many doctors, perhaps less so to those who listen to their patients.' The lack of communication in the past among those who treat patients with problems of the musculoskeletal system has been unnecessary, though financial and professional competition has made it understandable. The Physical Medicine Research Foundation, founded in 1985, aims to break down such barriers of communication-study, understanding, and treatment of the musculoskeletal system will progress much faster by coordinating the efforts of all concerned including doctors, chiropractors, osteopaths, and physiotherapists. The foundation awards grants preferentially to cooperative researchers from more than one discipline and organises multidisciplinary meetings. An important international meeting, drawing doctors and others from countries as far apart as Czechoslovakia and Australia, has just been held in Vancouver. Another is planned for Oxford in 1992. R M ELLIS
not numerous. The psychological characteristics of the two treatment groups were virtually identical. Both treatment approaches included educationmore so, if anything,.for patients treated in hospital than by chiropractic. Patients for whom litigation or compensation was at issue were, we pointed out, excluded from the trial. The absence of a clear relation between the number of treatments and outcome suggests that the benefit of chiropractic may be achieved with fewer treatments. We therefore doubt Joyce Wise's conclusion that more treatments might be effective. We dealt fully with the absence of a chiropractic effect in first time patients. It would be wrong to make too much of the one centre in which hospital treatment appeared slightly more effective because none of the differences at the various follow up intervals were even marginally significant. Turning to broader issues of research and policy, we did not, as Joyce Wise states, show that open access physiotherapy is as effective as, or better than, chiropractic but we agree that the availability of open access facilities in enabling early treatment and the effectiveness of nonmanipulative methods are important topics for further study. We agree with many of her other suggestions and those of Dr Sturge and Ms Bulstrode. Increasing the number of physiotherapists with manipulation skills in the NHS, improving the general conditions under which many physiotherapy departments work, increasing the precision of defining which patients benefit from chiropractic, and increasing the effectiveness of treatment in the many patients for whom manipulation is not an option are also obvious topics for further research and, naturally, we welcome Joyce Wise's commitment to assistance
from physiotherapists. Realistically, however, these questions are unlikely to be settled for several years. In the interim we believe that the substantial long term benefit of chiropractic in patients with chronic and severe low back pain makes it necessary to consider the availability of chiropractic to NHS patients now. T W MEADE
MRC Epidemiology and Medical Care Unit, Northwick Park Hospital, Harrow HAl 3UJ A 0 FRANK
Odstock Hospital, Salisbury SP2 8BJ
Northwick Park Hospital, Harrow HAI 3UJ
I Meade TW, Dyer S, Browne W, Townsend J, Frank AO. Low back pain of mechanical origin: randomised comparison of chiropractic and hospital outpatient treatment. Br Med J
Passive smoking
1990;300:1431-7. (2 June.)
AUTHORS' REPLY,-To deal first with technical points, Mr G P Graham and colleagues give a misleading figure for recruitment to the trial. Eligibility depended on the absence of contraindications to manipulation. We pointed out that, of those so eligible, 47% entered the trial. While bias of the sort Mr Graham and colleagues refer to is a theoretical possibility, there is no evidence for it and much against it. Indeed, they acknowledge that chiropractic is effective in some patients. Mr C H Brooks's comment about interobserver variability is largely irrelevant, because both measures of straight leg raising-included, incidentally, on orthopaedic advice-were made by the same observer, who had been trained in the technique. The principles are no different from those of, for example, measuring blood pressure and using the results. It was exactly to provide objective evidence in place of the impressions on which Mr M A Edgar relies that we carried out our trial. Few will give serious consideration to his suggestion that we should have deliberately included patients who might have been harmed by manipulation. Analysis by "intention to treat" will have largely taken account of Mr C G Greenough's point about incomplete treatment courses, though these were
1650
SIR,-Mr Norman Swan suggests that a motivation for smoke free workplaces in Australia comes from a series of workers' compensation payouts to people claiming illnesses caused by passive smoking.' He cites the case of Sean Carroll, a Melbourne bus driver. Your readers should be aware that no compensation was awarded for lung cancer which was in any way due to exposure to tobacco smoke. Sean Carroll lodged a claim for compensation under the Accident Compensation Act in January 1988. Carroll's claim form described his injury as "coughing" which affected the lungs and was due to "fumes from bus, aggravate lung condition." The medical certificate in support described the injury as "chest infection due to diesel fumes." Carroll was medically examined to substantiate his claim. During this examination his lung cancer was first diagnosed. Carroll's lawyers sought to amend the injuries alleged in the claim to include lung cancer due to exposure to cigarette smoke. The arbitrator held that Carroll was forced to cease work because of the effect of bus fumes on his lungs generally but did not make any finding in respect of a connection between lung cancer and exposure to environmental tobacco smoke. The arbitrator recommended that Carroll be placed on weekly payments of compensation. The Accident Compensation Commission and the State Insurance
Office appealed against this decision. At this time Carroll's claim was amended to include an allegation that his lung cancer had been produced, aggravated, accelerated, or exacerbated by "inhalation of cigarette smoke, exhaust emissions including bus emissions and air pollution." The State Insurance Office, Carroll's employer's insurers, made a commercial decision to settle Carroll's claim. The decision was the product of an exercise in mathematics and not of any conclusions about the health effects of exposure to environmental tobacco smoke, to which Carroll may have been exposed during the course of his employment. As a result of the insurers settling out of court the media assumed and reported that Carroll had been paid damages for an illness caused by so called passive smoking. This was not the case. In fact, during the course of the hearing evidence disclosed that Carroll drove his bus in a separate compartment from the passengers. Moreover, smoking was banned on Melbourne buses in 1976, 12 years before Carroll's compensation claim. The settlement of Carroll's case meant that the Accident Compensation Tribunal was not called on to decide whether Carroll's lung cancer was in any way attributable to exposure to tobacco smoke. The position remains that no court in Australia or anywhere else in the world has determined that there is any causal connection between exposure to environmental tobacco smoke and lung disease. A A WOOD Public affairs director
Rothmans International Services, Uxbridge UB9 5BL 1 Swan N. Australia invokes workers' compensation. Br Med J
1990;300:1357. (26 May.)
Radiolucent dentures SIR,-Mr George E Murty and Dr S Fawcett warn that dentures are radiolucent.' I believed that all medical practitioners knew that such material was radiolucent and that plain radiographs are useless as a diagnostic tool. Yet there seems to be a fundamental lesson to be learnt-namely, that proper attention should always be paid to the history of swallowing a foreign object which can lodge in the oesophagus with potential damage, however bizarre the history may be. As doctors we do have the advantage over veterinary surgeons in that patients-or their relatives-can talk to us. I have always practised and taught that when in doubt the only safe procedure is oesophagoscopy. This is becoming even more important in these days of increasing medical negligence litigation. Two personal cases may be of interest. A 7 year old boy was playing "cowboys and Indians" and pretended that he had been shot in the head by an arrow. He was running around with this in his mouth when he collided with a wall and broke the arrow. His mother brought him to hospital, saying that only one end of the arrow had been found. The boy was having some difficulty in swallowing and adamantly said that the arrow "had gone down." Examination of the oropharynx showed no trauma but oesophagoscopy found 15 cm of wooden arrow with a rubber sucker at the end, which was removed from the mid-oesophagus. An 18 year old swallowed a partial denture ih similar circumstances to those recorded by Mr Murty and Dr Fawcett. He was reassured by his local accident and emergency department but seven days later was admitted with massive haematemesis. At oesophagoscopy the denture was found to be embedded in the wall of the oesophagus, which it had perforated. At subsequent thoracotomy there was a septic mediastinitis with one end of the denture perforating the thoracic aorta. The aortic wall was infected and friable and would not take sutures. Sadly, the youth died. This also raises the important issue as to whether
BMJ VOLUME 300
23 JUNE 1990
