The National Audit of Cardiac Rhythm Management (CRM device) audit details clinical activity in the fields of:

  • pacemakers (for the treatment of blackouts and other symptoms);
  • implantable defibrillators (for the prevention of sudden cardiac death);
  • cardiac resynchronisation therapy (for the treatment of heart failure); and
  • catheter ablation (for the treatment of simple, complex atrial, and ventricular arrhythmias)

These current data provide a comparative measure of clinical procedure volumes within the populations of health geographies for clinical commissioning groups (CCGs) in England and Local Health Boards (LHB) in Wales, as well as showing change of activity over three areas. Data are shown as maps.

Indirectly standardised rate (per million population) of device implants in CCG and LHB areas in England and Wales. Rates are available for:

  • New implants of pacemakers
  • New implants of ICDs
  • Total implants of CRTs
  • Total implants of CRT-D and CRT-P
  • Total implants of high energy devices (ICDs and CRT-D devices)

Crude rate (per million population) of ablation procedures in CCG and LHB areas in England and Wales. Rates are available for:
  • Simple ablation
  • Complex atrial ablation
  • Ventricular ablation

Devices and ablation data: CRM audit, held by the National Institute for Cardiovascular Outcomes Research (NICOR)
Denominators for total, age-specific and reference crude rates: Office for National Statistics (ONS), mid year population estimates

In order to compare device implants accross geographical areas, the numbers of procedures were aggregated by either CCGs in England or LHBs in Wales, based on the residence of the patient. Procedures were aggregated by year and geography for defined device and ablation types.
Rates for devices are age adjusted using the indirect standardisation method. Expected deaths were calculated by multiplying the England & Wales age-specific implant rates (in 5-year age-bands) by the corresponding age-specific population for the corresponding year in each geography. The indirectly standardised rates are calculated by dividing the observed numbers of device implants by the expected numbers to create a standardised incidence ratio and the ratio is then multiplied by the England and Wales crude device implant rate to create the rates.
Byar's method1 gives very accurate approximate confidence intervals for counts based on the assumption of a Poisson distribution. This method was used to provide confidence around the indirectly standardised and crude rates.

1 Breslow NE, Day NE. Statistical methods in cancer research, volume II: The design and analysis of cohort studies. Lyon: International Agency for Research on Cancer, World Health Organization; 1987:69

Estimates for geographical areas are based on the patient's postcode of residence. Postcode assignment to a valid health area was over 97% complete for patient details treated at England or Wales hospitals in the CRM audit, so there are a small number of records that have not been mapped to a geographic location.
Where the numbers of procedures each year within geographies are less than 6, no rate has been calculated.