joint strategic needs assessment foundation profile - JSNA

Interative Hull Atlas: www.hullpublichealth.org/Pages/hull_atlas.htm More information: www.jsnaonline.org and www.hullpublichealth.org
Doncaster PCT has created a model which can be used to produce the estimated
number of people with diagnosed learning disabilities (Doncaster PCT 2008). In general
when such models have been produced, the model is based on research undertaken
elsewhere in the UK examining the prevalence of diagnosed disease in the community,
which has then been modelled and applied to different populations such as those living
in a particular PCT area. Therefore, the accuracy of the estimates depends on the
quality of the initial research and the modelling itself. If the original research did not
include very deprived areas, it is very difficult to generalise and apply the model to very
deprived areas like Hull. Furthermore, there are many reasons why the prevalence
could differ among practices (see section 12.13 on page 782 for more information).
Further information about problems associated with models can be found in the
Association of Public Health Observatories Technical Briefing (Association of Public
Health Observatories 2011) and in section 12.1 on page 770. Further information
about problems associated with models can be found in the Association of Public Health
Observatories Technical Briefing (Association of Public Health Observatories 2011) and
in section 12.1 on page 770. Therefore, just because practices have a particularly low
prevalence or a relatively large difference between the registers and the model, it does
not necessarily mean that they are performing badly in any way relative to other general
practices. Nevertheless, a comparison of the differences between the modelled
prevalence and the practice list registers can act as a starting point for investigation.
Practices with a low prevalence or a relatively large difference between the model and
the register estimates can be examined further and considered in relation to patient
characteristics using local knowledge. Differences might just reflect that the model is
not a very good fit for Hull. For reference, the mean age of practice patients (Table 28)
and mean deprivation scores (Table 49) for each practice may be examined.
The results of the modelling and the actual diagnosed numbers of patients with learning
disabilities are given in Table 62. The model does not necessarily represent the actual
number of people who should be diagnosed with learning disabilities for each practice; it
is only a guide. The characteristics of each practice differ and need to be considered.
The age-specific prevalence estimates for learning disabilities used by Doncaster PCT
are derived from research undertaken by Emerson and Hatton and they state that it is
an estimate of "true prevalence" defined as "people with severe learning disabilities who
would be known to services and people with less severe learning disabilities who
probably would not be known to services" (Emerson and Hatton 2004). Therefore, the
model estimates are considerably higher than the numbers on the practice registers as
the model includes those people with less severe learning disabilities who they expect
would not be known to services. Whilst clinical definitions may exist as to what
constitutes mild or moderate learning disabilities, in practice it may be difficult to
ascertain, and different definitions and how learning disabilities is defined could change
the estimates considerably, for example, including or not including “mild” learning
disabilities may influence the estimates considerably. Despite this potential problem
with definitions, the estimates used by Doncaster PCT are reasonably similar to those
given in Table 61. Assuming that two-fifteenths of those aged 5-19 years with learning
disabilities are aged 18-19 years, then it is estimated that 5,601 people who are
estimated to have learning disabilities are aged 18+ years from Table 61 which is not
Joint Strategic Needs Assessment Foundation Profile – Hull Health Profile: Release 3. March 2011. 164