Neurological Conditions: estimating the prevalence in Scotland of selected conditions using GP and Hospital Admissions datasets

2 Methodology

The neurological conditions included in this work were identified by members of NACNC. A list of the conditions for which data were requested and provided is shown in Annex C, with explanations for some data gaps.

General practice and hospital admissions data for the specified conditions were obtained from PHS. Full details of the methodology are available at Annex D and a process map is available at Annex E.

The general practice dataset comprises total counts of currently registered patients with a diagnosis ever recorded for each specified condition as of 8 April 2022. Data are not available for two of the 14 NHS Boards, and for 21 general practices from the other 12 NHS Boards. This dataset therefore covers general practices representing 72.7% of registered patients at the time of the data extract.

The hospital admissions dataset comprises total counts of people discharged from hospital with a diagnosis for each specified condition, recorded in any of the six diagnosis code positions, during the 20-year period prior to the end of 2019.

These datasets are not directly comparable: they derive from different data sources (SPIRE, which is sourced from general practice records, and Scottish Morbidity Records (SMR), which are sourced from hospital activity data) (see Annex D for more details). There are other differences (see Annex F for more details). However, the datasets complement each other, and together provide a broader picture of what national data can tell us about people diagnosed with neurological conditions. They also highlight where the data gaps might be, with respect to neurological conditions.

For some of the neurological conditions, comparative estimates were identified or calculated to provide additional context for the general practice and hospital admissions data. The comparative estimates included in this report derive from primary research considered robust or from specific disease registers.

Quality assurance support to inform the final version of the report was provided by PHS analysts and a neurologist member of NACNC, to whom access was granted to enable their assistance with data interpretation.