Chronic obstructive pulmonary disease (COPD): primary care data

Practice Team Information

The Practice Team Information (PTI) programme provided statistics on consultations for COPD in primary care in Scotland up to 2012/13. PTI data estimated the national prevalence of COPD (defined as those who have consulted a GP or practice nurse at least once during the year because of the condition) in 2012/13 for all ages to be 18.3 per 1000 patients registered for men and 19.8 for women. More detailed statistics are available for COPD consultations under the heading "Specific Conditions" on ISD's Practice Team Information web page. Because these figures are based on the number of people consulting they are likely to be an underestimate of the true prevalence of COPD. Chart 1
 Close  shows the estimated prevalence of COPD in Scotland (based on primary care consultations) by age group and gender using PTI data from 2012/13. Prevalence increases with age in both genders but is higher among men in the oldest age group.

These gender differences may be a result of the cohort effect produced by a historical lag of female smoking rates behind that of their male contemporaries. Whilst Scotland-specific data are not available to confirm such a trend, models describing the smoking epidemic, such as that presented by Lopez et al (1994) frequently refer to this female lag in the uptake of smoking. Such a lag may explain the lower prevalence of COPD in older women relative to men as a reflection of their lower rates of smoking in previous years. The earlier peak and subsequent decline of smoking rates in men might predict a decrease in COPD prevalence in men ahead of a similar decrease in women and thus may also contribute to this observed gender difference.

COPD is under-diagnosed in most populations, with a diagnosis often only being established in the moderate to severe stages of the disease. It should be noted that routine data may therefore underestimate the true extent of COPD within any given population. Chart 2 shows the estimated number of primary care consultations for COPD at Scotland level, using data from the Practice Team Information website. The number of GP consultations for COPD decreased between 2003/04 and 2007/08 but increased subsequently. Note that the number of consultations with health visitors and district nurses was not been available after 2005/06.

The collection of PTI data has now been discontinued, but the Scottish Primary Care Information Resource (SPIRE) - a collaboration between the Scottish Government and NHS National Services Scotland - will provide GP consultation data, and is expected in due course.

Quality and Outcomes Framework

The General Medical Services (GMS) contract for general practice, introduced in 2004, included a set of quality indicators within the voluntary Quality and Outcomes Framework (QOF) and data on these were published up to 2015/16. The QOF measured achievement against a range of evidence-based indicators and includes quality indicators for COPD. In 2015/16 2.29% of registered patients were included in the COPD register.

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. Subsequently patients could be included on both COPD and asthma registers, so comparisons in QOF-based prevalence before and after this time should be made with caution. Note that QOF data are aggregate and do not provide information on age or sex so that comparisons of COPD prevalence between areas using QOF cannot take account of differences in population age structure: higher prevalence may partly be due to an older population. Further information on using the data is given in Information for users of QOF register and prevalence data on the ISD website.