The British Journal of Psychiatry (2009)
195, 191–193. doi: 10.1192/bjp.bp.109.068452
Editorial
The psychiatric case register: noble past,
challenging present, but exciting future
Gayan Perera, Mishael Soremekun, Gerome Breen and Robert Stewart
Summary
Case registers have been fundamental to mental health
research from the early asylum studies onwards. Having
declined in popularity over the past 20 years, they are likely
to see a resurgence of interest with the advent of electronic
clinical records and the technological capacity to derive
anonymised databases from these.
Gayan Perera (pictured) is a South London and Maudsley/King’s College
London (SLAM/KCL) Biomedical Research Centre PhD student working on the
South London and Maudsley Biomedical Research Centre case register.
Mishael Soremekun is a research assistant at the KCL (Institute of Psychiatry)
SLAM/KCL Biomedical Research Centre Nucleus. Gerome Breen is a
postdoctoral research fellow with status of lecturer and SLAM/KCL Biomedical
Research Centre Genetics Coordinator. Robert Stewart is a clinical reader,
Head of the Section of Epidemiology and joint lead for the SLAM/KCL
Biomedical Research Centre Analytic Methods cross-cutting theme.
From the earliest asylum studies onwards, the ‘case register’ has
had a long and influential history in mental health research.
Recent moves towards fully electronic clinical records have
provided the opportunity for a new generation of case registers
supported by technological advances in the capacity to derive
anonymised research databases from routine records and to link
these with other data repositories. Having been involved in the
recent development of one such register, we thought it was timely
to review the history and applications of this research resource.
What is a case register?
Psychiatric case registers have been defined as ‘a patient-centred
longitudinal record of contacts with a defined set of psychiatric
services originating from a defined population’.1 The key elements
are similar to those for epidemiological research. However, as well
as providing important information on the distribution and
determinants of relatively rare disorders, case register research
can also be used to study outcomes in populations with these
disorders. The definition is broad and the level of detail on
‘contacts’ varies from simple information on demographic status,
diagnosis and in-patient service contact through to in-depth freetext data on symptomatology, professional interaction and
routinely applied fully structured assessment scales.
History of case registers
The principle behind case registers is simply the derivation and
testing of hypotheses from methodically recorded observations
which underpins scientific research. The original motivation to
create case registers was influenced by a combination of social,
political, professional and technological factors.2 Early national
case registers began in Norway (from 1936), Denmark and Iceland
(incorporating data from 1905 and 1907 respectively) and Israel
(1948), followed by several in the USA, Japan (Nagasaki),
Declaration of interest
The authors have been involved in the development and
application of a new psychiatric case register at the South
London and Maudsley NHS Foundation Trust, and Institute of
Psychiatry.
Australia (Victoria) and the UK (Camberwell and Aberdeen) in
the 1960s, and in Germany (Mannheim), The Netherlands
(Groningen) and Italy (Verona) in the 1970s (1973, 1973 and
1978 respectively).
The meetings of a joint inter-register committee from 1980 to
1986 was a high water mark in the UK, representing nine major
registers which existed at that time, funded by a variety of sources.
However, withdrawal of funding resulted in progressive and
complete closure from 1985 to 1987. It is beyond the scope of this
article to discuss in detail the reasons for this decline although
they include a loss of academic interest and decreasing integration
with clinical services, rendering the careful recording of researchrelevant data less acceptable to clinical staff. Case registers have
continued internationally including long-running programmes
in Groningen, Verona and Victoria and national registers in Israel,
Denmark and New Zealand.
Uses of case registers
Case registers contribute important data for service planning,
epidemiological, administrative and operational research.1 The
research contribution is clearly determined by the format of the
register and type of data collected. Case registers have been used
to investigate specific questions about health service delivery
and to evaluate care programmes and patterns of care, as well as
the validity of diagnostic tools and therapies. In epidemiological
research, they have particular advantages for describing morbidity
and service use associated with severe mental disorders because of
the problems of inadequate screening instruments for severe
disorders and of selective non-participation in community
surveys. Well-established case registers with informative individual
data are ideal for cohort studies, providing the principal means to
investigate factors predicting course and outcome in people with a
defined disorder as well as disorder incidence (particularly useful
for relatively rare and severe disorders) and predictors of this.3
Within outcomes research, case registers are particularly
important for evaluating costs of mental healthcare4 and, through
data linkage, mortality.5 Case register-based cohort studies are
most often historical in design (with outcome already ascertained
at the point of analysis commencement) and therefore offer cost
and logistical advantages. Some registers have been developed to
incorporate computer programs which can select cohorts from
the main body of register participants. Other uses of registers
include facilitating the recruitment of potential cases for case–
control investigations of potential risk factors.
191
Perera et al
Table 1 Description of papers indicating use of a psychiatric case register derived from a literature review carried out for
publications in five 2-year periods over 40 years
Study design
1964–65
1974–75
1984–85
1994–95
2004–05
Total
Case–control design within the register
1
1
3
7
12
Cohort study specifically for mortality
3
1
4
4
12
Cohort study with external comparison group
2
1
5
11
19
Cohort study within the register
1
3
5
14
24
47
Cross-sectional descriptive study
1
6
11
14
9
41
3
1
5
9
2
5
7
Observational intervention study (after and before reform)
Provision of cases with external controls
Provision of participants for intervention study
Total
2
In reviewing the application of case registers, we carried out a
PubMed and Google Scholar literature search for the MeSH term
‘psychiatric case registers’ screening 2-year periods over the past
five decades (2004–05, 1994–95, 1984–85, 1974–75, 1964–65).
The type of study design and objectives for the 151 articles
identified are summarised in Table 1. Over the 40-year period
there was a clearly marked increase in publications citing the
use of a case register, although this publication count remained
low considering the volume of mental health research. In general,
over the same period, the profile of study design has also changed
with a decline in simple cross-sectional descriptive analyses, and
an increase in cohort studies and the use of registers to provide
cases for case–control studies.
15
22
1
3
4
44
68
151
side-effects or secondary benefits not originally envisaged, which
trials are not powered to detect. Compared with most trials, case
registers also offer the advantages of a naturalistic setting and
therefore a broader and more generalisable evidence base.
A particular challenge for case registers concerns the
confidentiality and privacy of the information. Legal frameworks
for this vary between nations. In Norway, for example, a
psychiatric case register founded in 1916, covering a population
of 8 million, was abolished in 1988 because of public concerns
about confidentiality.8 A broader issue concerns stakeholder
participation and the need for case registers, where operating, to
address the questions most important to users and policy makers
rather than necessarily those of academics. A review of recent case
register output was critical in this respect and concluded that
important questions were not being addressed.9
Strengths and limitations
The principal strengths of case registers are their size and
prospective design, as well as the specific data (e.g. on course,
outcome, service use and cost) which tend not to be collected
elsewhere. Whether used for cohort studies or to generate cases
for case–control designs, case registers are most valuable for
research into disorders that are relatively rare (i.e. will not
appear with sufficient frequency in community studies) and with
a high chance of secondary care contact (i.e. where people with the
disorder who are known to secondary care services are reasonably
representative of total cases in the source community). In mental
health these principles apply most strongly to psychotic disorders
and least strongly to common mental disorders.
One limitation of case registers lies in the fact that the
information they contain is less likely to have been recorded in
a standardised way and is more inaccurate than that obtained in
a dedicated research project. Goodman6 noted that the diagnosis
recorded was particularly unreliable. However, a World Health
Organization collaborative study in the UK found a relatively high
(85%) concordance between a psychiatric case register and ICD–9
diagnosis.7 Maintaining accuracy (i.e. keeping records up to date)
is also a challenge.
A second limitation (inherent to observational research) is
that causal inferences are limited for observed associations,
principally because residual confounding can never be effectively
excluded as it can in a randomised controlled trial. However,
the advantage of a case register cohort study over a trial is that
the scale can be many magnitudes larger. For example, a single
centre’s case register may well have data on a larger number of
people with a particular disorder receiving different interventions,
and longer follow-up, than all international trials combined. This
is particularly important for rare outcomes such as medication
192
Looking to the future
There remains a need for internationally comparable morbidity
statistics (e.g. outlined in the European Commission’s recent DG
SANCO health plan; http://www.epha.org/a/3051). Early case
registers relied on considerable goodwill and close working
relationships between academic and clinical colleagues. However,
the major drawback was always that the data had to be manually
recorded and entered into computers, as these became available,
for analysis. This placed substantial limits on the depth of
information that could be contained and, therefore, on the
research output that could be generated. Several relatively recent
developments suggest that there may be substantial future
possibilities for this study design. First, with current trends
towards paperless clinical services, the volume of potential
information already in electronic format is vast. Second, in a
UK context at least, increasing requirements for service
providers to generate activity data for funding has meant that
clinical records are increasingly structured and available for
analysis. Third, technological advances now make it possible for
both free-text and fixed-variable fields to be searched and
extracted into anonymised databases for analysis (the requirements
for the recently developed South London and Maudsley case register). Fourth, similar developments are occurring in a variety of
health service settings with, in the UK, a national organisation
currently set up to consider the highly complex technical, ethical
and security issues surrounding database linkage (Connecting
for Health NHS Research Capability Programme; http://www.
connectingforhealth.nhs.uk/systemsandservices/research). Fifth, if
not already capable, current technology is at the cusp of being able
to handle the very large information resources generated when
The psychiatric case register
biological and imaging databases from nested research projects are
also incorporated: possibly the development that is most likely to
shape the case registers of the future.
2
Fryers T, Greatorex I. Case registers and mental health information systems.
In Measuring Mental Health Needs (eds G Thomicroft, CR Brewin, J Wing):
81–98. Gaskell, 1992.
3
Häfner H, Maurer K, Löffler W, an der Heiden W, Munk-Jørgensen P,
Hambrecht M, et al. The ABC Schizophrenia Study: a preliminary overview of
the results. Soc Psychiatry Psychiatr Epidemiol 1998; 33: 380–6.
4
Amaddeo F, Beecham J, Bonizzato P, Fenyo A, Tansella M, Knapp M. The
costs of community-based psychiatric care for first-ever patients. A case
register study. Psychol Med 1998; 28: 173–83.
5
Hiroeh U, Appleby L, Mortensen PB, Dunn G. Death by homicide, suicide, and
other unnatural causes in people with mental illness: a population-based
study. Lancet 2001; 358: 2110–2.
6
Goodman AB, Rahav M, Popper M, Ginath Y, Pearl E. The reliability of
psychiatric diagnosis in Israel’s Psychiatric Case Register. Acta Psychiatr
Scand 1984; 69: 391–7.
7
Jones SJ, Cooper JE, Davis N. Diagnostic validity and comparability. In
Psychiatric Case Registers in Public Health. A Worldwide Inventory (eds
GHMM Ten Horn, R Giel, H Gulbinat, JH Henderson): 175–8. Elsevier, 1986.
8
Munk-Jorgensen P, Kastrup M, Mortensen PB. The Danish Psychiatric register
as a tool in epidemiology. Acta Psychiatrica Scandinavica 1993; 82: 130–5.
9
Wierdsma AI, Sytema S, van Os JJ, Mulder CL. Case registers in psychiatry:
do they still have a role for research and service monitoring? Curr Opin
Psychiatry 2008; 21: 379–84.
Gayan Perera, MSc, Mishael Soremekun, MSc, Gerome Breen, PhD, Robert
Stewart, MD, MRCPsych, King’s College London (Institute of Psychiatry), UK
Correspondence: Robert Stewart, Section of Epidemiology (Box 60), Institute
of Psychiatry, King’s College London, De Crespigny Park, London SE5 8AF, UK.
Email: r.stewart@iop.kcl.ac.uk
First received 13 May 2009, final revision 13 May 2009, accepted 9 Jun 2009
Funding
All authors are funded by the NIHR Biomedical Research Centre for Mental Health, the
South London and Maudsley NHS Foundation Trust, and the Institute of Psychiatry, King’s
College London.
References
1
Ten Horn GHMM. A classification of different types of psychiatric case
registers. In Psychiatric Case Registers in Public Health (ed GHMM Ten Horn,
R Giel, WH Gulbinat, Henderson JH): 388–401. Elsevier, 1986.
193
The psychiatric case register: noble past, challenging present,
but exciting future
Gayan Perera, Mishael Soremekun, Gerome Breen and Robert Stewart
BJP 2009, 195:191-193.
Access the most recent version at DOI: 10.1192/bjp.bp.109.068452
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