- Email: [email protected]
Pain in neonates
CORRESPONDENCE
Sir—We are all, as potential patients, interested in how much the experience of surgeons and physicians impacts on clinical outcomes, not least because this may influence political moves to centralise or disperse health-care facilities. However, the research letter on this important issue by A C Williams (Nov 13, p 1697)1 and colleagues adds little to the debate. First, of 644 children undergoing cleft lip and palate repair, 456 had a speech assessment, of which complete surgical details were available for only 307, so that less than half contributed to analyses of the association between characteristics of the surgeon or surgery and speech outcome. Why the data were missing is unclear, but could represent considerable selection bias. Second, the outcome of interest—“poor speech outcome”—is not explicitly described; it is probably “a history of hypernasal speech”, but this sounds more like something in the past than an outcome. Third, the authors seem to prejudge the issue by referring to the operating experience of surgeons as “expertise”. And finally, if we could be convinced that the results for less than 50% of the original cohort are reliable, how are we to interpret “the inverse association . . . between the increasing number of palate repairs undertaken by a surgeon and poor speech outcome”? Does the odds ratio of 0·76 refer to the reduction in odds of a poor outcome for high versus low volume surgeons split into two groups (which, with an upper confidence limit of one, is hardly convincing), or is it the reduction in odds per extra operation undertaken (which would be more impressive)? *Charles P Warlow, Cathie Sudlow, Steff Lewis *Department of Clinical Neurosciences, University of Edinburgh, Bramwell Dott Building, Western General Hospital, Edinburgh EH4 2XU, UK; and Clinical Trial Service Unit, University of Oxford 1
Williams AC, Sandy JR, Thomas S, Sell D, Sterne JAC. Influence of surgeon’s experience on speech outcome in cleft lip and palate. Lancet 1999; 354: 1697–98.
Authors’ reply Sir—Unlike previous studies of the association between treatment and speech outcome in cleft lip and palate (CLP),1,2 our study was limited to complete unilateral CLP. Collection of data in the UK for children with unilateral CLP is hampered by lack of standardised record keeping,3 a poorly defined model of care, and the fact that some surgeons carry out very few CLP repairs. To reduce observer bias,
932
independent observers were used to assess outcome and collect surgical details. We defined outcome as a “history of hypernasal speech”. The presence of hypernasal speech after palate repair is a recognised measure of the quality of the primary surgery. If hypernasal speech is diagnosed it can be corrected with secondary velopharyngeal surgery. So the outcome was, in that sense, “in the past” for some children, but was nonetheless an outcome of their original surgery. Omission of these children, who had normal speech at the time of data collection, would have led to an underestimate of the true prevalence of poor primary palatal repair. Until now, sample sizes have been too small to separate the confounding effects of age at repair and technique from the influence of experience of the surgeon in cleft-palate care. We were able to establish outcome in 454 (71%) of the children identified as having been operated on. We found no evidence for a link between poor outcome and age of the child at the time of surgery, CLP repair workload of the surgeon, or type of repair, and think it very unlikely that systematic differences in the children who were not followed up biased the results of our study. In cleft-palate care, it is not until the child reaches the age of 5 years that the outcome of primary surgery (undertaken in the first year of life) can be measured objectively.4 The fact that complete data was available on only 307 (67%) of the children in whom outcome was measured, emphasises the need to improve record keeping. If record keeping improves, so will long-term audit. We agree that the use of the word “expertise” to equate with workload in the letter was unfortunate. In our original submission we used the terms “high volume” and “low volume” to indicate the CLP repair caseload of the surgeons. These terms were changed to “high expertise” and “low expertise” by The Lancet. We recognise that high caseload in itself does not ensure high quality: individual surgeons’ aptitude is Floated odds (log scale)
Surgeon experience
1·2 1·1 1 0·9 0·8 1
2 3 5 10 15 20 Number of operations (log scale)
Estimated trend (95% CI) of the odds of a history of hypernasal speech with increasing number of operations carried out by surgeon
also important. In a centralised model there is potential for one surgeon to operate badly on many cases, so that rigorous rolling audit will always be essential. However, surgeons with a small CLP repair caseload will never provide sufficient cases for such audit, especially since the outcomes for cleft lip and palate are subtle and long-term. Finally, we found that there was roughly a linear association between the log odds of hypernasal speech and the log of the number of operations carried out by the surgeon (figure). The figure was derived from a generalised additive model with three degrees of freedom.5 The odds ratio of 0·76 was per unit increase in the log (base e) of the number of operations, controlling for surgical technique and presurgical dental plate. This corresponds, for example, to an odds ratio of 0·83 (95% CI 0·69–1·00) comparing a surgeon who carried out 10 repairs with a surgeon who carried out five repairs. Alison Williams, *Jonathan Sandy, Jonathan Sterne *Division of Child Dental Health, University of Bristol, Dental School, Bristol BS1 2LY, UK (e-mail: [email protected]) 1
2
3
4
5
Rintala A, Haapenen M-L. The correlation between training and skill of the surgeon and re-operation rate for persistent cleft palate speech. Br J Oral Maxfac Surg 1995; 33: 295–93. Marrinan E, LaBrie R, Mulliken J. Velopharyngeal function in non-syndromic cleft palate: relevance of surgical technique, age at repair and cleft type. Cleft Palate Craniofac J 1998; 35: 95–100. Williams AC, Shaw WC, Sandy JR, Devlin HB. The surgical care of cleft lip and palate patients in England and Wales. Br J Plas Surg 1996; 49: 150–55. Atack N, Hathorn I, Mars M, Sandy J. Study models of 5 year old children as predictors of surgical outcome in unilateral cleft lip and palate. Eur J Orthodont 1997; 19: 165–70. Hastie T, Tibishirani RJ. Generalized additive models. New York: Chapman and Hall, 1990.
Pain in neonates Sir—The Jan 1 commentary1 by Malcolm Chiswick on assessment of pain in neonates should serve as a timely reminder to paediatricians that pain is an issue in newborn babies, and that they are obliged to implement more responsive and sensitive management guidelines, especially in neonatal intensive care units. Despite some inherent difficulties in assessment of pain in neonates, there cannot be many paediatricians, especially neonatologists, who are not aware that babies do experience pain and they show shortterm and long-term adverse physiological and behavioural responses after repeated exposure to painful stimuli.2 Analgesia should be considered
THE LANCET • Vol 355 • March 11, 2000
CORRESPONDENCE
Procedure
Routine
Frequent
Rare
Never
Intravenous cannulation Venepuncture Peripheral arterial line Central venous line Chest drain insertion Lumbar puncture Urethral catheterisation
1 (1·2%) 1 (1·2%) 2 (2·3%) 5 (5·8%) 55 (64%) 8 (9·3%) 2 (2·3%)
1 (1·2%) 1 (1·2%) 3 (3·5%) 2 (2·3%) 10 (11·6%) 8 (9·3%) 0
4 (4·7%) 2 (2·3%) 4 (4·7%) 11 (12·8%) 14 (16·3%) 7 (8·1%) 5 (5·8%)
80 (93·0%) 82 (95·3%) 77 (89·5%)* 68 (79·1%)* 7 (8·1%)* 63 (73·3%) 79 (91·9%)
*Procedures done only when the infant was already ventilated and receiving intravenous morphine, but given no additional analgesia.
Use of analgesia in 86 neonatal intensive care units
in the routine daily management of the neonates receiving intensive care. Sadly this does not seem to be the case. We did a survey of 86 neonatal units throughout the UK, looking at their use of analgesia for routine invasive procedures. All of these units had a minimum of four intensive care cots. Information was provided by their senior members of medical or nursing staff who were aware of the Unit’s routine management protocol. The findings (table) show that analgesia is still greatly underused for most painful procedures. Further research into the effectiveness and risks of analgesic drugs in very sick preterm infants is needed, but there is sufficient scientific evidence to justify the use of certain drugs3 with which clinicians have sufficient experience. Management of pain should be a quality issue in neonates just as much as in adults. Nilofer Sabrine, *Sunil Sinha Neonatal Services, South Cleveland Hospital, Middlesbrough TS4 3BW, UK (e-mail: [email protected]) 1 2
3
Chiswick ML. Assessment of pain in neonates. Lancet 2000; 355: 6–8. Anand KJS, Barton BA, McIntosh N, et al. Analgesia and sedation in preterm neonates who require ventilatory support: results from the NOPAIN Trial. Neonatal outcome and prolonged analgesia in neonates. Arch Pediatr Adoles Med 1999; 153: 331–38. Menon G, Walker CA, McIntosh N. Pharmacologica intervention. In: Sinha SK, Donn SM, eds. Manual of neonatal respiratory care. New York: Future Publishing Co Inc, 2000: 340–45.
Drunk driving and mental disorders Sir—Pirkko Räsänen and colleagues (Nov 20, p 1788) 1 report an association between age of onset of drunk driving and the probability of being a violent offender with severe psychiatric morbidity. They conclude that “interventions . . . are urgently needed” for this group. Yet they do not specifically examine severe psychiatric illness, and such assertions are therefore unfounded. Major mental disorders are usually regarded as psychoses and severe affective disorder, but the study
THE LANCET • Vol 355 • March 11, 2000
included any person with a hospitaltreated mental disorder from DSM IIIR categories 290–319, excluding only substance misuse disorders 303–305. This diagnostic spectrum not only includes many common neurotic conditions, but also several disorders defined either by behavioural disturbance (eg, disruptive behaviour disorders, 314) or the consequences of substance misuse (eg, alcohol withdrawal, delirium, hallucinosis, or amnestic disorder, 291). Axis II disorders such as antisocial personality disorder (301.70)— for which driving while intoxicated is a diagnostic criterion—have not been specifically excluded. Any association with offending or drunk driving could therefore be spurious. Räsänen and colleagues draw inferences about the pattern of offending in people with severe mental illness, though they have not specifically examined this group. Their conclusions should therefore be treated with caution.
cluster A (paranoid, schizoid, schizotypal), and borderline personality (cluster B), according to DSM-III-R. Individuals with any other DSM-III-R mental disorders were excluded (eg, psychoactive substanceuse disorders, psychoactive substanceinduced organic mental disorders, disruptive behaviour disorders, antisocial personality disorders) from statistical analyses. All people went through a detailed diagnostic A higher validation process. 2 proportion (n=8, 16%) of cohort members with hospital-treated mental disorder committed their first drunkdriving before 18 years of age, than did those without mental disorder (n=22, 6%; 2 test, p=0·017). Thus, we believe that psychiatric evaluation of young drunk drivers would be beneficial. *Pirkko Räsänen, Helinä Hakko Pauliina Valonen, Marjo-Riitta Järvelin Departments of *Psychiatry and Public Health Science and General Practice, University of Oulu, FIN-90210 Oulu, Finland; Department of Forensic Psychiatry, University of Kuopio, Niuvanniemi Hospital, Kuopio; and Department of Epidemiology and Public Health, Imperial College, School of Medicine, London, UK 1
2
Rantakallio P. The longitudinal study of the Northern Finland Birth Cohort of 1966. Pediatr Perinat Epidemiol 1988; 2: 59–88. Isohanni M, Mäkikyrö T, Moring J, et al. A comparison of clinical and research DSMIII-R diagnoses of schizophrenia in a Finnish national Birth Cohort: clinical and research diagnoses of schizophrenia. Soc Psychiatry Psychiatr Epidemiol 1997; 32: 303–08.
Michael Smith Department of Pscyhological Medicine, Academic Centre, Gartnavel Royal Hospital, Glasgow G12 0XH, UK 1
Räsänen P, Hakko H, Jarvelin M. Earlyonset drunk driving, violent criminality and mental disorders. Lancet 1999; 354: 1788.
Authors’ reply Sir—We thank Michael Smith for his constructive criticism. He points out the inadequacy of psychiatric diagnoses in the group of people with mental disorders. We undertook further analyses by more stringent diagnostic definitions to see whether age of onset for first registered drunk driving was lower among cohort members with mental disorders than among those without any psychiatric diagnoses in the Northern Finland 1966 births cohort (n=11 017).1 We used updated criminality data for cohort members up to the age of 32 years (n=400 drunk drivers). The mental disorder group included people being admitted for schizophrenia, schizophreniform disorders, brief reactive psychosis, atypical psychosis, major depression, personality disorders
Stalkers and the definition of violence Sir—Frank Farnham and colleagues (Jan 15, p 199)1 classified 50 stalkers according to their relationship with their victims (former sexual intimates, total strangers, and acquaintances) and showed that serious violence was significantly associated with former sexual intimates whereas it was not associated with strangers or with acquaintances. However, the definition by Farnham and colleagues of serious violence covers a very wide range of violence. This range is important because their new finding is the association between serious violence and intimacy. Other investigators2,3 have reported an association between violence itself and intimacy. There was no information about previous convictions in the study by Farnham and colleagues. Previous convictions are relevant: Mullen and colleagues2 showed that assault on victims by stalkers was predicted by previous convictions. If the former
933
Sir—We are all, as potential patients, interested in how much the experience of surgeons and physicians impacts on clinical outcomes, not least because this may influence political moves to centralise or disperse health-care facilities. However, the research letter on this important issue by A C Williams (Nov 13, p 1697)1 and colleagues adds little to the debate. First, of 644 children undergoing cleft lip and palate repair, 456 had a speech assessment, of which complete surgical details were available for only 307, so that less than half contributed to analyses of the association between characteristics of the surgeon or surgery and speech outcome. Why the data were missing is unclear, but could represent considerable selection bias. Second, the outcome of interest—“poor speech outcome”—is not explicitly described; it is probably “a history of hypernasal speech”, but this sounds more like something in the past than an outcome. Third, the authors seem to prejudge the issue by referring to the operating experience of surgeons as “expertise”. And finally, if we could be convinced that the results for less than 50% of the original cohort are reliable, how are we to interpret “the inverse association . . . between the increasing number of palate repairs undertaken by a surgeon and poor speech outcome”? Does the odds ratio of 0·76 refer to the reduction in odds of a poor outcome for high versus low volume surgeons split into two groups (which, with an upper confidence limit of one, is hardly convincing), or is it the reduction in odds per extra operation undertaken (which would be more impressive)? *Charles P Warlow, Cathie Sudlow, Steff Lewis *Department of Clinical Neurosciences, University of Edinburgh, Bramwell Dott Building, Western General Hospital, Edinburgh EH4 2XU, UK; and Clinical Trial Service Unit, University of Oxford 1
Williams AC, Sandy JR, Thomas S, Sell D, Sterne JAC. Influence of surgeon’s experience on speech outcome in cleft lip and palate. Lancet 1999; 354: 1697–98.
Authors’ reply Sir—Unlike previous studies of the association between treatment and speech outcome in cleft lip and palate (CLP),1,2 our study was limited to complete unilateral CLP. Collection of data in the UK for children with unilateral CLP is hampered by lack of standardised record keeping,3 a poorly defined model of care, and the fact that some surgeons carry out very few CLP repairs. To reduce observer bias,
932
independent observers were used to assess outcome and collect surgical details. We defined outcome as a “history of hypernasal speech”. The presence of hypernasal speech after palate repair is a recognised measure of the quality of the primary surgery. If hypernasal speech is diagnosed it can be corrected with secondary velopharyngeal surgery. So the outcome was, in that sense, “in the past” for some children, but was nonetheless an outcome of their original surgery. Omission of these children, who had normal speech at the time of data collection, would have led to an underestimate of the true prevalence of poor primary palatal repair. Until now, sample sizes have been too small to separate the confounding effects of age at repair and technique from the influence of experience of the surgeon in cleft-palate care. We were able to establish outcome in 454 (71%) of the children identified as having been operated on. We found no evidence for a link between poor outcome and age of the child at the time of surgery, CLP repair workload of the surgeon, or type of repair, and think it very unlikely that systematic differences in the children who were not followed up biased the results of our study. In cleft-palate care, it is not until the child reaches the age of 5 years that the outcome of primary surgery (undertaken in the first year of life) can be measured objectively.4 The fact that complete data was available on only 307 (67%) of the children in whom outcome was measured, emphasises the need to improve record keeping. If record keeping improves, so will long-term audit. We agree that the use of the word “expertise” to equate with workload in the letter was unfortunate. In our original submission we used the terms “high volume” and “low volume” to indicate the CLP repair caseload of the surgeons. These terms were changed to “high expertise” and “low expertise” by The Lancet. We recognise that high caseload in itself does not ensure high quality: individual surgeons’ aptitude is Floated odds (log scale)
Surgeon experience
1·2 1·1 1 0·9 0·8 1
2 3 5 10 15 20 Number of operations (log scale)
Estimated trend (95% CI) of the odds of a history of hypernasal speech with increasing number of operations carried out by surgeon
also important. In a centralised model there is potential for one surgeon to operate badly on many cases, so that rigorous rolling audit will always be essential. However, surgeons with a small CLP repair caseload will never provide sufficient cases for such audit, especially since the outcomes for cleft lip and palate are subtle and long-term. Finally, we found that there was roughly a linear association between the log odds of hypernasal speech and the log of the number of operations carried out by the surgeon (figure). The figure was derived from a generalised additive model with three degrees of freedom.5 The odds ratio of 0·76 was per unit increase in the log (base e) of the number of operations, controlling for surgical technique and presurgical dental plate. This corresponds, for example, to an odds ratio of 0·83 (95% CI 0·69–1·00) comparing a surgeon who carried out 10 repairs with a surgeon who carried out five repairs. Alison Williams, *Jonathan Sandy, Jonathan Sterne *Division of Child Dental Health, University of Bristol, Dental School, Bristol BS1 2LY, UK (e-mail: [email protected]) 1
2
3
4
5
Rintala A, Haapenen M-L. The correlation between training and skill of the surgeon and re-operation rate for persistent cleft palate speech. Br J Oral Maxfac Surg 1995; 33: 295–93. Marrinan E, LaBrie R, Mulliken J. Velopharyngeal function in non-syndromic cleft palate: relevance of surgical technique, age at repair and cleft type. Cleft Palate Craniofac J 1998; 35: 95–100. Williams AC, Shaw WC, Sandy JR, Devlin HB. The surgical care of cleft lip and palate patients in England and Wales. Br J Plas Surg 1996; 49: 150–55. Atack N, Hathorn I, Mars M, Sandy J. Study models of 5 year old children as predictors of surgical outcome in unilateral cleft lip and palate. Eur J Orthodont 1997; 19: 165–70. Hastie T, Tibishirani RJ. Generalized additive models. New York: Chapman and Hall, 1990.
Pain in neonates Sir—The Jan 1 commentary1 by Malcolm Chiswick on assessment of pain in neonates should serve as a timely reminder to paediatricians that pain is an issue in newborn babies, and that they are obliged to implement more responsive and sensitive management guidelines, especially in neonatal intensive care units. Despite some inherent difficulties in assessment of pain in neonates, there cannot be many paediatricians, especially neonatologists, who are not aware that babies do experience pain and they show shortterm and long-term adverse physiological and behavioural responses after repeated exposure to painful stimuli.2 Analgesia should be considered
THE LANCET • Vol 355 • March 11, 2000
CORRESPONDENCE
Procedure
Routine
Frequent
Rare
Never
Intravenous cannulation Venepuncture Peripheral arterial line Central venous line Chest drain insertion Lumbar puncture Urethral catheterisation
1 (1·2%) 1 (1·2%) 2 (2·3%) 5 (5·8%) 55 (64%) 8 (9·3%) 2 (2·3%)
1 (1·2%) 1 (1·2%) 3 (3·5%) 2 (2·3%) 10 (11·6%) 8 (9·3%) 0
4 (4·7%) 2 (2·3%) 4 (4·7%) 11 (12·8%) 14 (16·3%) 7 (8·1%) 5 (5·8%)
80 (93·0%) 82 (95·3%) 77 (89·5%)* 68 (79·1%)* 7 (8·1%)* 63 (73·3%) 79 (91·9%)
*Procedures done only when the infant was already ventilated and receiving intravenous morphine, but given no additional analgesia.
Use of analgesia in 86 neonatal intensive care units
in the routine daily management of the neonates receiving intensive care. Sadly this does not seem to be the case. We did a survey of 86 neonatal units throughout the UK, looking at their use of analgesia for routine invasive procedures. All of these units had a minimum of four intensive care cots. Information was provided by their senior members of medical or nursing staff who were aware of the Unit’s routine management protocol. The findings (table) show that analgesia is still greatly underused for most painful procedures. Further research into the effectiveness and risks of analgesic drugs in very sick preterm infants is needed, but there is sufficient scientific evidence to justify the use of certain drugs3 with which clinicians have sufficient experience. Management of pain should be a quality issue in neonates just as much as in adults. Nilofer Sabrine, *Sunil Sinha Neonatal Services, South Cleveland Hospital, Middlesbrough TS4 3BW, UK (e-mail: [email protected]) 1 2
3
Chiswick ML. Assessment of pain in neonates. Lancet 2000; 355: 6–8. Anand KJS, Barton BA, McIntosh N, et al. Analgesia and sedation in preterm neonates who require ventilatory support: results from the NOPAIN Trial. Neonatal outcome and prolonged analgesia in neonates. Arch Pediatr Adoles Med 1999; 153: 331–38. Menon G, Walker CA, McIntosh N. Pharmacologica intervention. In: Sinha SK, Donn SM, eds. Manual of neonatal respiratory care. New York: Future Publishing Co Inc, 2000: 340–45.
Drunk driving and mental disorders Sir—Pirkko Räsänen and colleagues (Nov 20, p 1788) 1 report an association between age of onset of drunk driving and the probability of being a violent offender with severe psychiatric morbidity. They conclude that “interventions . . . are urgently needed” for this group. Yet they do not specifically examine severe psychiatric illness, and such assertions are therefore unfounded. Major mental disorders are usually regarded as psychoses and severe affective disorder, but the study
THE LANCET • Vol 355 • March 11, 2000
included any person with a hospitaltreated mental disorder from DSM IIIR categories 290–319, excluding only substance misuse disorders 303–305. This diagnostic spectrum not only includes many common neurotic conditions, but also several disorders defined either by behavioural disturbance (eg, disruptive behaviour disorders, 314) or the consequences of substance misuse (eg, alcohol withdrawal, delirium, hallucinosis, or amnestic disorder, 291). Axis II disorders such as antisocial personality disorder (301.70)— for which driving while intoxicated is a diagnostic criterion—have not been specifically excluded. Any association with offending or drunk driving could therefore be spurious. Räsänen and colleagues draw inferences about the pattern of offending in people with severe mental illness, though they have not specifically examined this group. Their conclusions should therefore be treated with caution.
cluster A (paranoid, schizoid, schizotypal), and borderline personality (cluster B), according to DSM-III-R. Individuals with any other DSM-III-R mental disorders were excluded (eg, psychoactive substanceuse disorders, psychoactive substanceinduced organic mental disorders, disruptive behaviour disorders, antisocial personality disorders) from statistical analyses. All people went through a detailed diagnostic A higher validation process. 2 proportion (n=8, 16%) of cohort members with hospital-treated mental disorder committed their first drunkdriving before 18 years of age, than did those without mental disorder (n=22, 6%; 2 test, p=0·017). Thus, we believe that psychiatric evaluation of young drunk drivers would be beneficial. *Pirkko Räsänen, Helinä Hakko Pauliina Valonen, Marjo-Riitta Järvelin Departments of *Psychiatry and Public Health Science and General Practice, University of Oulu, FIN-90210 Oulu, Finland; Department of Forensic Psychiatry, University of Kuopio, Niuvanniemi Hospital, Kuopio; and Department of Epidemiology and Public Health, Imperial College, School of Medicine, London, UK 1
2
Rantakallio P. The longitudinal study of the Northern Finland Birth Cohort of 1966. Pediatr Perinat Epidemiol 1988; 2: 59–88. Isohanni M, Mäkikyrö T, Moring J, et al. A comparison of clinical and research DSMIII-R diagnoses of schizophrenia in a Finnish national Birth Cohort: clinical and research diagnoses of schizophrenia. Soc Psychiatry Psychiatr Epidemiol 1997; 32: 303–08.
Michael Smith Department of Pscyhological Medicine, Academic Centre, Gartnavel Royal Hospital, Glasgow G12 0XH, UK 1
Räsänen P, Hakko H, Jarvelin M. Earlyonset drunk driving, violent criminality and mental disorders. Lancet 1999; 354: 1788.
Authors’ reply Sir—We thank Michael Smith for his constructive criticism. He points out the inadequacy of psychiatric diagnoses in the group of people with mental disorders. We undertook further analyses by more stringent diagnostic definitions to see whether age of onset for first registered drunk driving was lower among cohort members with mental disorders than among those without any psychiatric diagnoses in the Northern Finland 1966 births cohort (n=11 017).1 We used updated criminality data for cohort members up to the age of 32 years (n=400 drunk drivers). The mental disorder group included people being admitted for schizophrenia, schizophreniform disorders, brief reactive psychosis, atypical psychosis, major depression, personality disorders
Stalkers and the definition of violence Sir—Frank Farnham and colleagues (Jan 15, p 199)1 classified 50 stalkers according to their relationship with their victims (former sexual intimates, total strangers, and acquaintances) and showed that serious violence was significantly associated with former sexual intimates whereas it was not associated with strangers or with acquaintances. However, the definition by Farnham and colleagues of serious violence covers a very wide range of violence. This range is important because their new finding is the association between serious violence and intimacy. Other investigators2,3 have reported an association between violence itself and intimacy. There was no information about previous convictions in the study by Farnham and colleagues. Previous convictions are relevant: Mullen and colleagues2 showed that assault on victims by stalkers was predicted by previous convictions. If the former
933