- Email: [email protected]
Is there an evidence-based practice for burns?
Burns 24 (1998)
ELSEVIER
29-33
Is there an evidence-based practice for burns? Charmaine Childs” MRC
Trauma
Group.
NWIRC
and Regional
Paediatric
Burns
Unit, Booth
Accepted
Hall UK
Children’s
11 August
Hospital,
Charlestow
Road, Biackley,
Manchester
M9 2AA,
1997
Abstract
Doubts anldquestionsabout clinical decisionmakingneed to be answered.Evidence-basedmedicineaimsto provide answers by systematicallyfinding information from the vast assortmentof researchpapersin the literature and bringing it together to use in everyday practice and in the best interestsof the patient. Although clinical (and experimental) studieshave a variety of methodologies,rangingfrom small descriptivestudiesto large multi-centre trials all are vital in describingor posingquestions about the array of responseselicited when humanbeingsare burned and subsequentlytreated. When it comesto treatment (be it a drug, a dressing,an enteral feed for example)the ‘gold standard’for establishingwhether it is effective is the randomized controlled trial (RCT). Using contemporary information retrieval systems and the numerous establishments set up to help track down information of researchin medicinerelevant to health practice and policy the numbersof RCTs, systematicreviewsand meta-analysesof burn care have been established.Whilst the numbersof RCTs are increasingthere is little evidencethat burn care is an evidence-based practice. 0 1998Elsevier ScienceLtd for ISBI. All rights reserved.
It. Introduction
In recent years there have been radical developments in the promotion of a discipline that brings the best evidence from clinical and health care research to those working with patients as well as to those involved in making policy decisions which affect patient care. Evidence-based medicine [l] is the process whereby questions about health care practice are answered by tracking down the best evidence available and by doing so practitioners also reflect upon and evaluate thleir own performance. The organizational structure for promotion of what, for many, is a relatively new concept and working practice has been supported through the NHS Research and Development Programme [Z] with a number of key institutions providing information strategies on evidence-based medicine. The UK Cochrane Centre based in Oxford [3] was established in 1992 and forms part of an international collaboration to build, maintain anId disseminate a database of systematic reviews of randomized controlled trials (RCTs) [4] of _____ *Correspondence should be addressed to: Dr C. Childs, Regional Paediatric Burns Unit, Booth Hall Children’s Hospital, Charlestown Road, Blackley, Manchester M9 2AA, UK 0305-4179/98/$19.00 + 0.00 0 1998 Elsevier PII: SO305-4179(97)00089-2
Science
Ltd for ISBI. All rights
lhealth care. This is the Cochrane Database of Systematic Reviews, regularly updated as an electronic journal and held in most hospital libraries. In 1993 the NHS Centre for Reviews and Dissemination, based in York was established with a primary role for commissioning reviews on aspects of health care of specific importance to the NHS, and principally in areas relating to effectiveness and cost effectiveness [5]. The results and recommendations of completed systematic reviews are held in the database. Requests for information about systematic reviews in aspects of patient care, health care management, health care organization and policy are made available to those within the NHS. By early 1995 the first centre for evidence-based medicine was set up to teach and support those interested (through courses and workshops) in learning a.bout, and practising, evidence-based medicine. With the launch of the new, Journal for Evidence-based Medicine [6], it is clear from the contents pages that subject titles of systematic reviews of RCTs in medicine are disparate. In the field of burn care, however, there is little evidence that systematic reviews are underway. Whether the apparent lack of systematic reviews in burns is due to a failure to appreciate the importance of evaluating the results of RCTs as a systematic review, or due to a paucity of RCTs within the reserved.
Is there an elideme-based
30
practice for h~m~s?lB~ms
specialtij is unclear. Whatever the reason the new politics of health for the future encourages clinical decision making based on evidence of benefit and this would sleem eminently sensible. The aim of this paper is to examine the burns literature to determine the nature and extent of the literature on RCTs in burn care and the implications for an evidence-based practice for burns.
2. Materials
and methods
In an attempt to establish the numbers of RCTs published on burn care a number of strategies were used. The first were A4edkze searches of definite RCTs using the search strategy given in Table 1. The second was by handsearching two specialist burns journals for RCTs where publications of RCTs were likely to appear. Next a request was made to the NHS Centre for Reviews and Dissemination (NHS, CRD, University of York) for references of published systematic reviews and meta-analyses of burn care, held in the NHS CRD database. Systematic reviews are identified by scanning of major databases such as Current Contents and Mediine as well as sources of grey literature [7]. Data from the National Research Register (NRR), an element of the Information Systems Strategy (ISS) of the NHS Research and Development Programme, provided records of projects taking place within the NHS on burn care.2.1 Medline searches One of the Medline searches was undertaken in collaboration with the Intensive Care National Audit Research Centre (ICNARC) at the library of the British Medical Association, London. A second, local search of the literature was undertaken at the library of the University Hospital of South Manchester (UHSM). The first search, using the search strategy listed in Table I. Search terms used definite RCTs using Medlim Set _-..
to
identify
publications
Search ..--
primary,
criteria
~~ .~~~~. RCT pt” RCTsi Random allocation/ Double-blind method/ Single-blind method/ 1 or 2 or 3 or 4 or 5 Limit 6 to human Burns/ 8 and 7
1 2 3 4 5 6 I 8 9 “pt, publication
of
type.
24 (1998)
29-33
Table 1 covered the period 1991-1995, the second, updated search also using the search strategy of Table 1 was repeated for the period 1990-1997 but this time limited to publications in the IEnglish language. The searches were undertaken using different Medline Software. 2.2 Handsearching of publications The search of each issue of a medical journal (back and current issues) for RCTs is considered to be the ‘gold’ standard for identifying RCTs or references made to them. The type of clinical trial can be categorized as a definite, quasi, probable or possible RCT depending on the method of random allocation of subjects and patients. Within the speciality of intensive care, ICNARC have completed, or are currently engaged in, organized handsearching the wide literature relating to intensive care and trauma and this includes the specialist burns literature. All articles, abstracts and letters in an issue are read by a voluntary handsearcher. Most are nurses or doctors commissioned to do the work, usually handsearching one journal for a period of 5 years. Some handsearch prospectively, as new issues of a specific journal are published. Photocopies of the relevant RCT (whether a definite primary, quasi probable or possible) either as a full paper, as a reference in a letter or abstract are made and sent to the ICNARC co-ordinators. With the co-operation of ICNARC all primary articles of RCTs published in the journals Burns (from the first issue in 1974 to 1995) and the Journal of Burn Care and Rehabilitation, (from 1985 to 1995) were identified and documented. Expert reviews were excluded.
3. Results The first search strategy using Medline (Ovid Software) listed in Table 1, revealed 57 publications of delinite primary RCTs of burn treatmlent between 1991 and 1995. The second (using Dialog Windows software) search for the period 1990-1997, and modified by limiting the search to publications in the English Language, revealed 56 RCTs. (Table 2). The results of handsearching the two specialist burns journals, Bums and Journal of Bum Care and Rehabilitation for definite, quasi or possible IRCTs, are given in Table 2. During the 23 years since the first publication of Bums in 1974 (to 1995) 61 RCTs have been published (Table 3). During the 1970s and early 1980s only a small number of RCTs were published but the numbers have gradually increased since 1989. Most (62%) of the clinical trials published in Burns have
C. ChildslBurns Table
2. Sources
used to identify
RCTs
and systematic
reviews
RCTs”
Period
I\iledlineA MedIke’
57 56
1991-1995 1990-Jan
Burns
61
1974-1995
50
1985-1995
of Bum
~Cunrr and Rehahilitntim
University of York, and Dissemination NRR
NHS
Centre
for Reviews
31
in burn care
Source
Journal
24 t.1998) 29-33
Comments
1997
2
1991 onwards
1
1993 onwards
Ovid software. Search limited to human studies Dialog (Windows) software. Search limited to human studies written in the English language Handsearching of all journals since publication. Majority (62%) of RCTs on either wound healing or dressings Handsearched. Two to eight RCTs published each year in a wide range of topics Systematic reviews on aspects of burn care -- 1. Nutritional intervention in acute illness and surgery [8] 2. Treatment of severe burns using cultured autografts [9] A double-blind method RCT-cohort study ______
“‘Includes primary definite, quasi and possible RCTs - definite indicates evidence of ‘true’ randomization.; the basis of, for example, days of the week or birth date; for possible RCTs the method of random allocation +Search restricteli to primary, definite RCTs using search strategy in Table 1.
been on the subject of burn wound dressings and healing. Handsearching of the journal, Jourrzal of Burn Care and Rehabilitation revealed 50 RCTs during the 10 years, 1985-1995. Since the late 1980s there have been from two to eight RCTs published each year with 34% of publications on dressings and wound healing, suggesting publication of a somewhat broader range of clinical trials than in the journal Burns. Two references only to systematic reviews of burn care were identified from the York, NHS, CRD database [S,9] (Table 2). The records were compiled from the database of the International Nehvork of Agencies for Health Technology Assessment (INAIITA). Data from the NRR revealed six records of major projects studying burn patients. Of these there was one RCT, one non RCT, three case/cohort control studies and one laboratory and clinical programme of injury research which included burns research (Table 2).
4. Discussion
The scope for undertaking clinical research is enormous and studies can be broadly categorized [lo]. For example most studies looking at the effect of external factors on human beings (drug treatments, therapy) tend to be longitudinal (retrospective or prospective), investigating an effect over time. This might be by observation of the patients response to ,a phenomenon such as burn injury, or by a planned intervention such as the effect of a new dressing on wound healing. Clinical trials fall within the category of longitudinal studies and are prospective studies designed to examine the relative efficacy of a standard treatment (control) with another (test) therapy, often a new one. Although not all clinical trials ensure random allocation of patients into the control and tests groups,
quasi suggests is less clear
random
allocation
on
the benefit of randomization is that chance plays a part in assignment to a group which is comparable in known as well as unknown factors. These known and unknown factors are as likely to influence outcome as the treatment being tested [lo]. If patients in a clinical trial are randomly assigned to one of two groups (based for example on a computer generated list of random numbers) any bias in allocation to the group can be eliminated. This ensures that probabilities obtained from statistical analysis of the two treatments (control and test) will be valid. The RCT is thus the ‘gold standard’ for determining whether a preventive, screening, diagnostic, therapeutic, intervention does more good than harm to the patient [ll]. However, unearthing numerous reports of the results of RCTs in any given subject is time consuming. In some specialities a large number elf RCTs (published and unpublished) may have been done, but the outcomes may vary. Being able to summarize the results of lots of RCTs is important to establish whether the ‘odds’ [4] of a treatment is beneficial especially for the patient who is to receive the treatment. Clinicians need to be sure that the treatment they give to their patient is the best lpossible. A statistical synthesis of the results of a series of RCTs can be made as a meta-analysis [12]. This is a review of evidence and published as a systematic review. Unlike the expert review which is bound to have an element of bias, the systematic review comments only on accumulated facts which have been collected in a systematic way. This i,s the way to establish whether a clinical intervention is beneficial to the patient ie treatment is based on evidence rather than consensus or prejudice. So what of the effects of treatment in burn care? Is there any evidence of an emerging evidence-based practice to help clinicians be confident that the patient is receiving the best treatment? Apart from two systematic reviews unearthed from the NHS CRD
Is there an el/idence-hosed
32
practice
database, the weight of evidence is against there being an evidence-based practice. However, the fundamental elements appear to be present in the form of the RCT. The speciality of Burn Care in the UK is a small one. I\Tevertheless, and as the results from the searches of the literature indicate, the number of published RCTs are increasing even in the face of stiff competition for funding of studies in hospitals today and despite apparently smaller numbers of patients to enrol into our studies. It is also known from the recently developed database of the European Burns Association [13], that research in particular aspects of burn care is flourishing. Whilst some may feel that the subjects being studied at present are not broad enough it must be recognized that within the realms of wound cover Table 3. Primary the journal Bums
RCTs (definite, quasi and possible) from 1977 to 1995 (total = 61)
Year
Subject
1971 1978 1979 1980 1981 1982 1983 LO84
D RF RF D Ts
2
-
0
I985
D FG D RF D D D E 6
1986 1987 1988 1989
1990
of trialt
Number
published”
in
for burns?/Burm
24 (1998)
29-33
and repair, burns clinicians and scientists have access to a sizable literature, past and recent, which should now be reviewed in a systematic way. For aeons burns wounds have been treated by a multitude of preparations and dressings. The time is fast approaching to start knowing which one is good and which ones do no good at all.
Acknowledgements
The author would like to thank MS Julia Langham and Mr Tim Binstead of the Intensive Care National Audit and Research Centre, Londlon, UK, for their enthusiastic co-operation and help with the handsearching and literature searches. Thanks also to MS Donna T. Wright of the University Hospital of South Manchester Library for her help with the hospital library search.
of publications
Appendix 5. Organizations
D
5 2
S/D D
and contacts
o The National Research Register - contact Mr Sam Brown, NHS Executive, R.D.D. Room GW59, Quarry House, Quarry Hill, Leeds LS2 7UE, UK. l The UK Cochrane Centre NHS R&D Programme, Summertown Pavilion, Middle Way, Oxford OX2 7LG, UK. o NHS Centre for Reviews and Dissemination University of York, York YOl 5DD, UK. o Intensive Care National Audit and Research Centre, Tavistock House, Tavistock Square, London WCZH 9HX, UK.
RF 1991
1992
1993 1994 1995
D W RF 83 M D D W 1 D s P
2 2
References 4 [l]
3
“No RCTs published before 1977. @tudy type: studies on: D, wound dressings/topical treatment; ‘W, wound healing; R/F, resuscitation/fluid therapy; I, infectioniimmunology; F/G, fecding/gastrointestina! tract; E, endocrinology: M, metabolism; G. general care: S, surgery; P, prevention.
Sack&t, D. L. and Haynes, R. B., On the need for evidencebased medicine. Evidence-bused Med, 1995, 1 (1). 5-6. [ 21 NHS Executive. Pronzotbzg Clinical Ejjkctiveness: a Framework for Action in and Tllrough the NHS. NHS Executive, 1996. ]3] Editorial. Cochrane’s legacy. The Lancet 1992; 340, 1131-1133. 1.41 Chalmers I. and Altman D. G., Systematic Reviews. London: BMJ Publishing Group, 1995. 151 Haines, A. and Iliffe, S., Innovations in services and the appliance of science. Managers and doctors should both seek evidence of effectiveness. BI: Med. L, 1995, 310, 815-816. 1161 Sackett, D. L., EBM notebook: on some clinically useful measures of the effects of treatment. E&fence-based Med., 1996, 1 (2), 37-38. [7] Naylor-, C. D., Grey zones of clinical practice: some limits to evidence-based medicine. The Lance& 1995, 34.5, 840-844.
C. ChildslBurm (S] Paulsen. I~. M. and Splett, P. L., Summary document of nutrition intervention in acute illness: burns and surgery. J Anz Diefetic Sot, 1991, Supplement, S15-S19. [9] ICowley, D. E., Cultured S/&r. Canberra: Australian Institute of Health and Welfare, 1992, p. 3. lo] Campbell M. J. and Machin, D., Medical Statistics, 2nd ed. Chichester: Wiley, 1993.
24 (1998) [ll]
29-33
33
Chalmers, I.. Dickerson, K. and Chalmers. T. C., Getting to grips with Archie Cochrane’s agenda. B: Meal. J., 1992, 305, 56-88. [12] Eysenck; H. J., Meta-analysis or best-evidence synthesis. J. Evalrtntiot7 Clirz. Prucfice, 1995, 1 (I), 2!9-36. ,-131 Childs, C.. The Europm~z Directory of Bums Resewch. Bums. 1998, 24, 25-28.
ELSEVIER
29-33
Is there an evidence-based practice for burns? Charmaine Childs” MRC
Trauma
Group.
NWIRC
and Regional
Paediatric
Burns
Unit, Booth
Accepted
Hall UK
Children’s
11 August
Hospital,
Charlestow
Road, Biackley,
Manchester
M9 2AA,
1997
Abstract
Doubts anldquestionsabout clinical decisionmakingneed to be answered.Evidence-basedmedicineaimsto provide answers by systematicallyfinding information from the vast assortmentof researchpapersin the literature and bringing it together to use in everyday practice and in the best interestsof the patient. Although clinical (and experimental) studieshave a variety of methodologies,rangingfrom small descriptivestudiesto large multi-centre trials all are vital in describingor posingquestions about the array of responseselicited when humanbeingsare burned and subsequentlytreated. When it comesto treatment (be it a drug, a dressing,an enteral feed for example)the ‘gold standard’for establishingwhether it is effective is the randomized controlled trial (RCT). Using contemporary information retrieval systems and the numerous establishments set up to help track down information of researchin medicinerelevant to health practice and policy the numbersof RCTs, systematicreviewsand meta-analysesof burn care have been established.Whilst the numbersof RCTs are increasingthere is little evidencethat burn care is an evidence-based practice. 0 1998Elsevier ScienceLtd for ISBI. All rights reserved.
It. Introduction
In recent years there have been radical developments in the promotion of a discipline that brings the best evidence from clinical and health care research to those working with patients as well as to those involved in making policy decisions which affect patient care. Evidence-based medicine [l] is the process whereby questions about health care practice are answered by tracking down the best evidence available and by doing so practitioners also reflect upon and evaluate thleir own performance. The organizational structure for promotion of what, for many, is a relatively new concept and working practice has been supported through the NHS Research and Development Programme [Z] with a number of key institutions providing information strategies on evidence-based medicine. The UK Cochrane Centre based in Oxford [3] was established in 1992 and forms part of an international collaboration to build, maintain anId disseminate a database of systematic reviews of randomized controlled trials (RCTs) [4] of _____ *Correspondence should be addressed to: Dr C. Childs, Regional Paediatric Burns Unit, Booth Hall Children’s Hospital, Charlestown Road, Blackley, Manchester M9 2AA, UK 0305-4179/98/$19.00 + 0.00 0 1998 Elsevier PII: SO305-4179(97)00089-2
Science
Ltd for ISBI. All rights
lhealth care. This is the Cochrane Database of Systematic Reviews, regularly updated as an electronic journal and held in most hospital libraries. In 1993 the NHS Centre for Reviews and Dissemination, based in York was established with a primary role for commissioning reviews on aspects of health care of specific importance to the NHS, and principally in areas relating to effectiveness and cost effectiveness [5]. The results and recommendations of completed systematic reviews are held in the database. Requests for information about systematic reviews in aspects of patient care, health care management, health care organization and policy are made available to those within the NHS. By early 1995 the first centre for evidence-based medicine was set up to teach and support those interested (through courses and workshops) in learning a.bout, and practising, evidence-based medicine. With the launch of the new, Journal for Evidence-based Medicine [6], it is clear from the contents pages that subject titles of systematic reviews of RCTs in medicine are disparate. In the field of burn care, however, there is little evidence that systematic reviews are underway. Whether the apparent lack of systematic reviews in burns is due to a failure to appreciate the importance of evaluating the results of RCTs as a systematic review, or due to a paucity of RCTs within the reserved.
Is there an elideme-based
30
practice for h~m~s?lB~ms
specialtij is unclear. Whatever the reason the new politics of health for the future encourages clinical decision making based on evidence of benefit and this would sleem eminently sensible. The aim of this paper is to examine the burns literature to determine the nature and extent of the literature on RCTs in burn care and the implications for an evidence-based practice for burns.
2. Materials
and methods
In an attempt to establish the numbers of RCTs published on burn care a number of strategies were used. The first were A4edkze searches of definite RCTs using the search strategy given in Table 1. The second was by handsearching two specialist burns journals for RCTs where publications of RCTs were likely to appear. Next a request was made to the NHS Centre for Reviews and Dissemination (NHS, CRD, University of York) for references of published systematic reviews and meta-analyses of burn care, held in the NHS CRD database. Systematic reviews are identified by scanning of major databases such as Current Contents and Mediine as well as sources of grey literature [7]. Data from the National Research Register (NRR), an element of the Information Systems Strategy (ISS) of the NHS Research and Development Programme, provided records of projects taking place within the NHS on burn care.2.1 Medline searches One of the Medline searches was undertaken in collaboration with the Intensive Care National Audit Research Centre (ICNARC) at the library of the British Medical Association, London. A second, local search of the literature was undertaken at the library of the University Hospital of South Manchester (UHSM). The first search, using the search strategy listed in Table I. Search terms used definite RCTs using Medlim Set _-..
to
identify
publications
Search ..--
primary,
criteria
~~ .~~~~. RCT pt” RCTsi Random allocation/ Double-blind method/ Single-blind method/ 1 or 2 or 3 or 4 or 5 Limit 6 to human Burns/ 8 and 7
1 2 3 4 5 6 I 8 9 “pt, publication
of
type.
24 (1998)
29-33
Table 1 covered the period 1991-1995, the second, updated search also using the search strategy of Table 1 was repeated for the period 1990-1997 but this time limited to publications in the IEnglish language. The searches were undertaken using different Medline Software. 2.2 Handsearching of publications The search of each issue of a medical journal (back and current issues) for RCTs is considered to be the ‘gold’ standard for identifying RCTs or references made to them. The type of clinical trial can be categorized as a definite, quasi, probable or possible RCT depending on the method of random allocation of subjects and patients. Within the speciality of intensive care, ICNARC have completed, or are currently engaged in, organized handsearching the wide literature relating to intensive care and trauma and this includes the specialist burns literature. All articles, abstracts and letters in an issue are read by a voluntary handsearcher. Most are nurses or doctors commissioned to do the work, usually handsearching one journal for a period of 5 years. Some handsearch prospectively, as new issues of a specific journal are published. Photocopies of the relevant RCT (whether a definite primary, quasi probable or possible) either as a full paper, as a reference in a letter or abstract are made and sent to the ICNARC co-ordinators. With the co-operation of ICNARC all primary articles of RCTs published in the journals Burns (from the first issue in 1974 to 1995) and the Journal of Burn Care and Rehabilitation, (from 1985 to 1995) were identified and documented. Expert reviews were excluded.
3. Results The first search strategy using Medline (Ovid Software) listed in Table 1, revealed 57 publications of delinite primary RCTs of burn treatmlent between 1991 and 1995. The second (using Dialog Windows software) search for the period 1990-1997, and modified by limiting the search to publications in the English Language, revealed 56 RCTs. (Table 2). The results of handsearching the two specialist burns journals, Bums and Journal of Bum Care and Rehabilitation for definite, quasi or possible IRCTs, are given in Table 2. During the 23 years since the first publication of Bums in 1974 (to 1995) 61 RCTs have been published (Table 3). During the 1970s and early 1980s only a small number of RCTs were published but the numbers have gradually increased since 1989. Most (62%) of the clinical trials published in Burns have
C. ChildslBurns Table
2. Sources
used to identify
RCTs
and systematic
reviews
RCTs”
Period
I\iledlineA MedIke’
57 56
1991-1995 1990-Jan
Burns
61
1974-1995
50
1985-1995
of Bum
~Cunrr and Rehahilitntim
University of York, and Dissemination NRR
NHS
Centre
for Reviews
31
in burn care
Source
Journal
24 t.1998) 29-33
Comments
1997
2
1991 onwards
1
1993 onwards
Ovid software. Search limited to human studies Dialog (Windows) software. Search limited to human studies written in the English language Handsearching of all journals since publication. Majority (62%) of RCTs on either wound healing or dressings Handsearched. Two to eight RCTs published each year in a wide range of topics Systematic reviews on aspects of burn care -- 1. Nutritional intervention in acute illness and surgery [8] 2. Treatment of severe burns using cultured autografts [9] A double-blind method RCT-cohort study ______
“‘Includes primary definite, quasi and possible RCTs - definite indicates evidence of ‘true’ randomization.; the basis of, for example, days of the week or birth date; for possible RCTs the method of random allocation +Search restricteli to primary, definite RCTs using search strategy in Table 1.
been on the subject of burn wound dressings and healing. Handsearching of the journal, Jourrzal of Burn Care and Rehabilitation revealed 50 RCTs during the 10 years, 1985-1995. Since the late 1980s there have been from two to eight RCTs published each year with 34% of publications on dressings and wound healing, suggesting publication of a somewhat broader range of clinical trials than in the journal Burns. Two references only to systematic reviews of burn care were identified from the York, NHS, CRD database [S,9] (Table 2). The records were compiled from the database of the International Nehvork of Agencies for Health Technology Assessment (INAIITA). Data from the NRR revealed six records of major projects studying burn patients. Of these there was one RCT, one non RCT, three case/cohort control studies and one laboratory and clinical programme of injury research which included burns research (Table 2).
4. Discussion
The scope for undertaking clinical research is enormous and studies can be broadly categorized [lo]. For example most studies looking at the effect of external factors on human beings (drug treatments, therapy) tend to be longitudinal (retrospective or prospective), investigating an effect over time. This might be by observation of the patients response to ,a phenomenon such as burn injury, or by a planned intervention such as the effect of a new dressing on wound healing. Clinical trials fall within the category of longitudinal studies and are prospective studies designed to examine the relative efficacy of a standard treatment (control) with another (test) therapy, often a new one. Although not all clinical trials ensure random allocation of patients into the control and tests groups,
quasi suggests is less clear
random
allocation
on
the benefit of randomization is that chance plays a part in assignment to a group which is comparable in known as well as unknown factors. These known and unknown factors are as likely to influence outcome as the treatment being tested [lo]. If patients in a clinical trial are randomly assigned to one of two groups (based for example on a computer generated list of random numbers) any bias in allocation to the group can be eliminated. This ensures that probabilities obtained from statistical analysis of the two treatments (control and test) will be valid. The RCT is thus the ‘gold standard’ for determining whether a preventive, screening, diagnostic, therapeutic, intervention does more good than harm to the patient [ll]. However, unearthing numerous reports of the results of RCTs in any given subject is time consuming. In some specialities a large number elf RCTs (published and unpublished) may have been done, but the outcomes may vary. Being able to summarize the results of lots of RCTs is important to establish whether the ‘odds’ [4] of a treatment is beneficial especially for the patient who is to receive the treatment. Clinicians need to be sure that the treatment they give to their patient is the best lpossible. A statistical synthesis of the results of a series of RCTs can be made as a meta-analysis [12]. This is a review of evidence and published as a systematic review. Unlike the expert review which is bound to have an element of bias, the systematic review comments only on accumulated facts which have been collected in a systematic way. This i,s the way to establish whether a clinical intervention is beneficial to the patient ie treatment is based on evidence rather than consensus or prejudice. So what of the effects of treatment in burn care? Is there any evidence of an emerging evidence-based practice to help clinicians be confident that the patient is receiving the best treatment? Apart from two systematic reviews unearthed from the NHS CRD
Is there an el/idence-hosed
32
practice
database, the weight of evidence is against there being an evidence-based practice. However, the fundamental elements appear to be present in the form of the RCT. The speciality of Burn Care in the UK is a small one. I\Tevertheless, and as the results from the searches of the literature indicate, the number of published RCTs are increasing even in the face of stiff competition for funding of studies in hospitals today and despite apparently smaller numbers of patients to enrol into our studies. It is also known from the recently developed database of the European Burns Association [13], that research in particular aspects of burn care is flourishing. Whilst some may feel that the subjects being studied at present are not broad enough it must be recognized that within the realms of wound cover Table 3. Primary the journal Bums
RCTs (definite, quasi and possible) from 1977 to 1995 (total = 61)
Year
Subject
1971 1978 1979 1980 1981 1982 1983 LO84
D RF RF D Ts
2
-
0
I985
D FG D RF D D D E 6
1986 1987 1988 1989
1990
of trialt
Number
published”
in
for burns?/Burm
24 (1998)
29-33
and repair, burns clinicians and scientists have access to a sizable literature, past and recent, which should now be reviewed in a systematic way. For aeons burns wounds have been treated by a multitude of preparations and dressings. The time is fast approaching to start knowing which one is good and which ones do no good at all.
Acknowledgements
The author would like to thank MS Julia Langham and Mr Tim Binstead of the Intensive Care National Audit and Research Centre, Londlon, UK, for their enthusiastic co-operation and help with the handsearching and literature searches. Thanks also to MS Donna T. Wright of the University Hospital of South Manchester Library for her help with the hospital library search.
of publications
Appendix 5. Organizations
D
5 2
S/D D
and contacts
o The National Research Register - contact Mr Sam Brown, NHS Executive, R.D.D. Room GW59, Quarry House, Quarry Hill, Leeds LS2 7UE, UK. l The UK Cochrane Centre NHS R&D Programme, Summertown Pavilion, Middle Way, Oxford OX2 7LG, UK. o NHS Centre for Reviews and Dissemination University of York, York YOl 5DD, UK. o Intensive Care National Audit and Research Centre, Tavistock House, Tavistock Square, London WCZH 9HX, UK.
RF 1991
1992
1993 1994 1995
D W RF 83 M D D W 1 D s P
2 2
References 4 [l]
3
“No RCTs published before 1977. @tudy type: studies on: D, wound dressings/topical treatment; ‘W, wound healing; R/F, resuscitation/fluid therapy; I, infectioniimmunology; F/G, fecding/gastrointestina! tract; E, endocrinology: M, metabolism; G. general care: S, surgery; P, prevention.
Sack&t, D. L. and Haynes, R. B., On the need for evidencebased medicine. Evidence-bused Med, 1995, 1 (1). 5-6. [ 21 NHS Executive. Pronzotbzg Clinical Ejjkctiveness: a Framework for Action in and Tllrough the NHS. NHS Executive, 1996. ]3] Editorial. Cochrane’s legacy. The Lancet 1992; 340, 1131-1133. 1.41 Chalmers I. and Altman D. G., Systematic Reviews. London: BMJ Publishing Group, 1995. 151 Haines, A. and Iliffe, S., Innovations in services and the appliance of science. Managers and doctors should both seek evidence of effectiveness. BI: Med. L, 1995, 310, 815-816. 1161 Sackett, D. L., EBM notebook: on some clinically useful measures of the effects of treatment. E&fence-based Med., 1996, 1 (2), 37-38. [7] Naylor-, C. D., Grey zones of clinical practice: some limits to evidence-based medicine. The Lance& 1995, 34.5, 840-844.
C. ChildslBurm (S] Paulsen. I~. M. and Splett, P. L., Summary document of nutrition intervention in acute illness: burns and surgery. J Anz Diefetic Sot, 1991, Supplement, S15-S19. [9] ICowley, D. E., Cultured S/&r. Canberra: Australian Institute of Health and Welfare, 1992, p. 3. lo] Campbell M. J. and Machin, D., Medical Statistics, 2nd ed. Chichester: Wiley, 1993.
24 (1998) [ll]
29-33
33
Chalmers, I.. Dickerson, K. and Chalmers. T. C., Getting to grips with Archie Cochrane’s agenda. B: Meal. J., 1992, 305, 56-88. [12] Eysenck; H. J., Meta-analysis or best-evidence synthesis. J. Evalrtntiot7 Clirz. Prucfice, 1995, 1 (I), 2!9-36. ,-131 Childs, C.. The Europm~z Directory of Bums Resewch. Bums. 1998, 24, 25-28.