Wide variations found in drug prescribing to older people

20 Jun 2014 | Health Quality Intelligence

A New Zealand Medical Journal article reports wide variations across the country in the dispensing of benzodiazepine and antipsychotic drugs to older people.

The Health Quality & Safety Commission (the Commission) report, Variation in benzodiazepine and antipsychotic use in people aged 65 years and over in New Zealand, found that benzodiazepine dispensing rates ranged from 80 out of 1000 people aged 65 and over at West Coast District Health Board (DHB) to 130 out of 1000 people at Auckland DHB.

Antipsychotic dispensing ranged from 18 out of 1000 people aged 65 and over at Waitemata DHB to 32 out of 1000 people at Canterbury DHB.

Auckland, Nelson Marlborough and Canterbury DHBs had the highest figures for dispensing both benzodiazepines and antipsychotics.

Disease rates do not vary this much by area, so health system factors are likely to be behind the wide level of variation.

The rates of dispensing of benzodiazepine and antipsychotics climbed steeply with age, with those aged 85 and above nearly four times more likely to be dispensed antipsychotics than those aged 65-74. People aged 85 and over were more than twice as likely to be dispensed benzodiazepines than those aged 65-74 years.

Women were significantly more likely to be dispensed benzodiazepine and antipsychotics than men.

The report covered the period from 2008 to 2012. Dispensing rates increased over the four years of the report.

In older people, antipsychotics are sometimes used to manage behaviours in people with dementia such as wandering, despite a lack of evidence of their effectiveness. Benzodiazepines are often used to treat insomnia where non-drug interventions have failed.

Benzodiazepine and antipsychotics carry a substantially higher risk of adverse effects in older people. Side effects can include impaired functional ability, agitation, confusion, urinary incontinence, and impaired balance leading to falls.

Use of both classes of medicine is associated with an increased risk of death.

Guidelines from the Ministry of Health and the Royal Australian and New Zealand College of Psychiatrists recommend the medicines be given only in short courses for specified symptoms in selected cases, with doses decreased and then stopped wherever feasible.

The article concludes that DHBs who have high prescribing rates should examine the causes of this in their area, and design interventions to reduce the rates.

The report was commissioned in 2013, after the Commission released information on polypharmacy – the prescribing of many medicines, or inappropriate prescribing - in its Atlas of Healthcare Variation. The Atlas of Healthcare Variation shows variation in the health care received by people in different geographical regions. It aims to stimulate debate by highlighting variation, rather than making judgments about why this variation exists or whether it is appropriate.

The Atlas on polypharmacy showed that the use of benzodiazepines and antipsychotic medicines increased with age, and that prescribing varied across New Zealand.

Atlas information can be seen on the Commission’s website: www.hqsc.govt.nz/atlas.

Download a copy of the frequently asked questions here.

Last updated 23/06/2014