One in every four GP prescriptions for cancer drug is never filled by the patient it is issued to, according to new NHS research which ranks different drugs according to patient compliance.
A study of general practice prescribing data found only 73.5% of drugs for malignant disease and immunosuppression were redeemed, compared with an average of 98.5% for all other drugs.
A report by the NHS Information Centre compared for the first time the number of prescriptions written by GPs with the number dispensed, giving a ‘redemption rate' that allows patient compliance with different drugs to be assessed.
The study examined the redemption rate for 19 groups of medication prescribed at 145 practices in England between 2004 and 2008. It found that most prescriptions are redeemed by patients, although the mean average redemption rate fell slightly from 99.6% in 2004 to 98.5% in 2008, a decrease that the report authors said ‘may be due in part to improved recording systems in GP practices.'
Generally redemption rates were higher for practices with a large proportion of prescriptions for the elderly and lower for practices with a high proportion of prescriptions given to patients aged under 16 – even though both groups are exempt from the prescription fee.
The only consistent significant correlation found between deprivation and redemption rates was that redemption rates for antipsychotic drugs were higher in more deprived area, at 82.0% in the most affluent quartile and 87.9% in the most deprived in 2007.
The authors said the poor redemption rate for cancer drugs ‘are of concern given the possible consequences of a failure to take these medications as prescribed for the patients.'
Compliance for antipsychotics was also poor, with only 85.1% of all GP prescriptions redeemed.
Tim Straughan, chief executive of the NHS Information Centre, said: ‘A patient may not redeem their prescription for several reasons such as deciding they don't need the medication, or a reluctance to take a drug they have had side effects from previously. A patient may have lost their prescription or obtained their medication through another source – such as during a stay in hospital. The cost of prescriptions may also be a factor.'
The report can be viewed at: www.ic.nhs.uk/pubs/presccompliance