Asthma: key data sources

Primary care data

Practice Team Information (PTI)

The Practice Team Information (PTI) programme (formerly Continuous Morbidity Recording) provides statistics on consultations in primary care in Scotland for a range of conditions including asthma. The sample is not sufficiently large to provide reliable prevalence estimates below national level. Data on asthma from PTI are reviewed in the primary care data page in this section. A general overview of the data provided by PTI is available from the Overview of key data sources: Practice Team Information section in the ScotPHO site. The ISD PTI data section on the ISD website provides further information and commentary on consultations for asthma.

Quality and Outcomes Framework (QOF)

The General Medical Services contract for general practices, introduced in 2004, includes a voluntary Quality and Outcomes Framework (QOF). The QOF measures achievement against a range of evidence-based indicators and includes quality indicators for COPD. The advantage of this data source is its national level of coverage; one important disadvantage is that only aggregated data are available, so that it is not possible to adjust for age or other differences when making comparisons between populations. QOF data on asthma are briefly reviewed in the primary care data page in this section. Detailed statistics on quality achievements and on prevalence of COPD in the QOF are available from the Quality and Outcomes Framework (QOF) section of the ISD website.

Until April 2006, QOF definitions did not allow patients to be on both asthma and COPD registers – thus patients with a degree of reversible airways disease were not included on the COPD register. From 1st April 2006 patients with COPD and reversible airways obstruction should also be included on the asthma register. As a result, comparisons in QOF-based prevalence before and after this time should be made with caution.

Prescribing data

Data on the quantity of asthma related items prescribed by primary care services in Scotland are available from ISD's Prescribing Programme. At present incomplete recording and capture of CHI numbers from prescriptions means that there is a lack of information on the number of individuals prescribed these drugs. It is also not currently possible to know whether a specific prescription was given for asthma.

Secondary care data

Data on hospital inpatient and day case discharges for asthma are held in the Scottish Morbidity Record (SMR01) database. Data from SMR01 are presented in the secondary care data page in this section An overview of SMR01 data is available on the ScotPHO site under the heading Overview of key data sources: Hospital discharges. Data on outpatient consultations are held in the SMR00 database but these do not include complete information on diagnoses. While the specialty of the outpatient service used is recorded, patients with asthma may be seen in a number of different specialties (mainly respiratory and general medical).

Mortality data

Mortality data by underlying cause of death (including asthma) are published annually by the General Register Office for Scotland (GROS). Asthma mortality data are briefly reviewed in the mortality data page in this site. Detailed statistics for individual causes of death are published by GROS in the annual GROS Vital Events Reference Tables, in Table 6.4 (Section 6).

Surveys and international comparisons

Scottish Health Survey

The Scottish Health Survey was carried out in 1995, 1998 and 2003 and has now moved to a continuous design, with the first report due in late 2009. The survey includes questions (reported in chapter 8) on doctor diagnosed asthma and self-reported wheeze in adults over 16 years, based on the MRC respiratory symptom questionnaire. Mean FEV1, FVC and PEFR was recorded in a subset of respondents. A sub-sample of children received a nurse visit, at which lung function was measured in children over 7 years and children over 11 years tested for total and house dust specific IgE antibodies. An overview of the Scottish Health Survey is available in the ScotPHO resources section. Detailed results are available from the website of the 2003 Scottish Health Survey.

ISAAC

The International Study of Asthma and Allergies in Childhood (ISAAC) is an international survey that has collected internationally comparable data from children since 1991. The most recent wave of surveys examined 798 685 children aged 13–14 years from 233 centres in 97 countries, and 388 811 children aged 6–7 years from 144 centres in 61 countries and was conducted between 2000 and 2003. The results were reported by Lai et al (2009).