Forensic epidemiology

DEFINITION OF EPIDEMIOLOGY

 

Epidemiology is “the study of the distribution and determinants of health related states or events in populations, and the application of this study to control health problems”. It has been called the basic science of public health. 

      Epidemiological methods can be used to identify groups of the population who are at highest risk for disease, to monitor population rates of exposures and diseases and to recognize and control epidemics. Epidemiology is important in numerous fields of study, including occupational health and safety, infectious diseases, cardiovascular disease, gastrointestinal disease, cancer, nutrition, injury prevention and the environment.  

History: 

Epidemiological methods have been used for centuries to investigate dis-
ease occurrences. For example, epidemiology was used in the investigation of scurvy by James Lind in 1747, scrotal cancer by Percival Pott in 1775, cholera by John Snow in 1849, and pellagra by Joseph Gold-berger around 1914. More recently, epidemiology has provided evidence for the association between fluoride
use and dental caries, cigarette smoking and lung cancer, tampon use and toxic shock syndrome, and HPV exposure and cervical cancer; it has also been used to investigate health risks associated with proximity to power lines, exposure to dietary supplements, and use of hormone replacement therapy.

These examples are of exposure disease associations considered to  be naturally occurring phenomena, in that these diseases were not intentionally caused in order to harm human populations. However, we have now entered a new era in public health and epidemiology that involves the investigation of health related criminal cases such as delib-
erate poisonings and bioterrorist events. In order to continue protecting the public’s health, agencies that may seem unlikely partners need to work closely together. Epidemiology
can serve as a link between disciplines such as law, medicine, pharmacy, statistics, city planning, and emergency management services to achieve the goal of a healthy public.
A discipline called forensic epidemiology is serving as the pivotal point between these disciplines.  

Disciplines that may become involved in a forensic epidemiology investigation

1. Local and state health departments
2. Police and firefighters
3. State bureaus of investigation
4. Emergency management services
5. Hospitals and health clinics
6. State laboratories
7. Pharmacists
8. Federal Bureau of Investigation
9. National Guard and other military units
10. Centers for Disease Control and Prevention
11. Federal Emergency Management Administration
12. United States Department of Agriculture
13. Department of Homeland Security
14. Attorney General’s Office. 

 Forensic Epidemiology is a new discipline that combines medical, public health and  law enforcement information to create situational awareness of illness that could indicate a natural event, an accident, a crime, or a national security matter. The threat of chemical, radiological, and biological agents may create ill victims in which recognition and response must happen simultaneously for lives to be saved and contamination limited. Information collection, analysis, decision-support, needed medications, mitigation strategies, and rapid surge capacity must be rapidly and accurately implemented for the event to be recognized and the victims saved.  

        Forensic Epidemiology differs from standard epidemiology in that it includes law enforcement information on terrorist subjects, goals, capabilities, and likely venues of attack in its analysis of illness patterns. Forensic epidemiology analysis may produce law enforcement actions, investigations, or result in criminal charges; which must be done with both speed and accuracy to serve the needs of national security organizations. Emergency Medical Services and emergency departments will be the first to see these victims and therefore have the first opportunity to detect disease patterns that correspond to deliberate attacks and therefore are vital components of the national strategy for counter-terrorism. Failures at this level can have far-reaching consequences.

 

Epidemiology – the study of prevalence of health and disease in populations and

factors affecting these – has, we suggest, at least two main benefi ts for forensic

mental health. First, in providing information on the prevalence of mental dis-

orders in offender populations, it can highlight where and how adequate resources

for mentally disordered offenders are lacking. Second, it can provide information

on risk factors for adverse outcomes, and thus, will, in turn, assist in

prevention.

In the fi rst category, the knowledge, for example, that the prevalence of severe

mental illness is 4% in adult prisoners (Fazel and Danesh, 2002), or nearly 30%

in young girls in detention (Fazel et al., 2008a), will assist policy-makers and

public health managers to plan mental health services in prisons. Even when

research has not been carried out for a particular prison, systematic reviews and

meta-analyses could inform prison mental health services without policy-makers

having to wait for a local survey. Low-income and smaller countries might benefi t

particularly from such data, as research funds are often inadequate to carry out

national studies. The problem of prisoners with undetected and untreated severe

mental illness may continue to worsen in absolute numbers – over 70% of the

countries included in a recent survey of worldwide prison numbers reported

increases in their inmate populations (Walmsley, 2005). In the mid-1990s, Torrey

(1995), in a n editorial in the American Journal of Public Health, noted that jails

had become the main psychiatric institutions in the USA, but it is likely that

prisons in many more countries now share this dubious distinction.

Secure hospital numbers have been increasing markedly in many Western

countries (Priebe et al., 2008). Taylor and colleagues (Butwell et al., 2000;

Jamieson et al., 2000; Taylor et al., 2008) have provided prevalent informa-

tion on the psychiatric and physical morbidity among patients in high-security

Fazel et al.

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psychiatric hospitals, both as trends over time and as comparisons across jurisdic-

tions within the UK; others, using a pragmatic and descriptive approach, have

emphasised the shifts in the level of secure occupancy in health service facilities

(e.g. Rutherford and Duggan, 2008). Subgroups of these populations, such as

younger (Fazel et al., 2008c) and older patients (Fazel and Grann, 2002), have

been the subject of research interest from our group. Other work has provided

useful information on the needs of women (Coid et al., 2000a; Yourstone et al.,

2008), ethnic minorities (Coid et al., 2000b) and other subgroups in forensic

hospitals (Coid et al., 2001).

Some may criticise this type of research as ‘bean-counting’, and that slicing

up these populations in more and more ways provides little new useful informa-

tion. In our view, the justifi cation for each study needs to be clear and relate in

some way to service planning and treatment needs.

In the second category, the potential for harm prevention ranges through

deliberate self-harm, suicide, repeat offending, violence within institutions, illness

relapse and rehospitalisation. Much of the epidemiological research on risk factors

has focused on repeat offending, which has been accompanied by a wave of com-

mercialisation of the assessment of recidivism risk. Hence, this work is in need

of careful systematic reviews, preferably by groups independent of those people

who developed specifi c risk assessment instruments. The validity of these instru-

ments for women (Grann, 2000), ethnic minorities (Långström, 2004), younger

and older offenders (Långström and Grann, 2000; Fazel et al., 2006), and general

psychiatric populations needs to be considered separately. A problem may be that

some of the risk factors in these instruments are poorly supported epidemiologi-

cally, by being based on inadequately designed studies. Insuffi ciently robust

research design in the fi eld of risk factor research might provide misleading

information that could do substantial harm to assessed individuals or potential

victims (Buchanan and Leese, 2001).

Even when well done, research producing more extreme results is more likely

to become published in high-profi le journals, and consequently, the effect of a

particular risk factor may be overstated (Young et al., 2008). One example is

maternal smoking during pregnancy, commonly suggested as an early risk factor

for a range of adverse outcomes in exposed offspring, including poorer academic

achievement and criminality. However, recent studies suggest that maternal

smoking during pregnancy, although clearly a public health problem, does not in

itself increase the risk for all negative outcomes seen among exposed individuals

(D’Onofrio et al., 2007; D’Onofrio et al., 2008; Gilman et al., 2008; D’Onofrio

et al., 2009). These latter studies control not only for measured factors affecting

maternal smoking and negative outcomes (i.e. confounders), but also for unmea-

sured familial confounding (which could include temperament, cognitions and

attitudes) by comparing exposed children with related (e.g. siblings or cousins)

unexposed individuals (Rutter, 2007). It is not possible to control for familial

confounding when comparing exposed individuals with unrelated comparison

What is the role of epidemiology for forensic psychiatry?

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DOI: 10.1002/cbm

283

subjects, which has been the dominant approach in epidemiology. More sophis-

ticated designs are needed to examine the complexity in the development of

psychiatric illness from a ‘multivariate soup’ of interrelated factors on genetic,

other biological, interpersonal and societal levels (Kendler, 2008).

Another example is the basic question of whether schizophrenia and other

psychoses are risk factors for repeat offending. A highly cited meta-analysis by

Bonta and colleagues suggested that they were not (Bonta et al., 1998), and one

risk assessment instrument even scores it as protective against recidivism. The

studies, however, that formed the basis of this view compared schizophrenia and

other psychoses with a restricted range of other mental disorders, so these fi ndings

need to be viewed with caution. To conclude, for example, that schizophrenia is

not associated with recidivism when your comparison group is dominated by

individuals with Psychopathy Checklist-Revised psychopathy leaving a high-

security hospital seems premature. It also fl ies in the face of epidemiological

studies in the general population (Fazel and Grann, 2006; Taylor, 2008). What

would give a clearer picture is a control group, which has been screened for not

having any mental disorders – no such study was included in the meta-analysis

by Bonta et al. (1998). We identifi ed one previous study, which was underpowered,

in prisoners that compared individuals with schizophrenia with individuals

without any diagnosis (Teplin et al., 1994). Therefore, we recently investigated

this question in community offenders, and our results suggested, in contrast to

the conclusions of Bonta et al. (1998), that schizophrenia was modestly associated

with repeat offending. The association disappeared when adjustments were made

for age, gender, previous violent crime, index violent crime, and drug and alcohol

co-morbidity (Grann et al., 2008).

An additional concern with forensic mental health research is the large grey

literature that exists, because much research is commissioned by government

bodies and prison authorities, and never published in peer-reviewed journals. This

may skew the development of knowledge in our fi eld, and systematic reviews are

particularly valuable in addressing this problem. For example, in reviewing risk

factors for suicide in prisoners, a recent review identifi ed a large number of studies

in the grey literature that together contributed about 30% of the suicide cases

included (Fazel et al., 2008b).

In summary, we think that epidemiology continues to have a role in forensic

mental health, but to do so, research questions need to be more clearly articulated

and, preferably, linked to public health priorities. Research studies must be appro-

priately designed (including being adequately powered), and systematic reviews

are necessary to make sense of the collective evidence.

References

Bonta J, Law M, Hanson K (1998) The prediction of criminal and violent recidivism among

mentally disordered offenders: a meta-analysis. Psych ol og ical Bull et in 123: 123–142.

Fazel et al.

Copyright © 2009 John Wiley & Sons, Ltd 19: 281–285 (2009)

DOI: 10.1002/cbm

284

Buchanan A, Leese M (2001) Detention of people with dan

 

 

 

Ref: https://nciph.sph.unc.edu/focus/vol2/issue5/2-5ForensicEpi_issue.pdf 

https://www.researchgate.net/publication/24255145_What_is_the_role_of_epidemiology_for_forensic_psychiatry