Current guidelines for chronic heart disease and type two diabetes do not provide enough information on the benefits and harms of treatment to enable doctors to make decisions for individual patients, researchers have concluded.
A lack of detail on ‘absolute effect sizes’ of recommended medicines is stopping doctors from deviating from the guidelines where appropriate, the German researchers said.
Analysis of a range of guidance from English and German-speaking countries, including the UK, found 75% of the total 144 recommendations on pharmacotherapy had no data on absolute effect sizes for benefit or harm.
Some guidelines did include this type of information – with 22% of individual drug recommendations having one or more average effect sizes for either benefit or harm.
However only a tiny number – three recommendations – featured details about effect sizes that were easy to find, the study showed.
The 13 guidelines reviewed as part of the study included the third Joint British Societies guidelines on cardiovascular disease and the most recent NICE recommendations on management of type 2 diabetes – both of which were found to contain no detail on effect sizes for any of the drug treatments included.
Writing in the Journal of Evidence in Clinical Practice, the researchers from the Institute of General Practice in Erlangen concluded: ‘Current clinical practice guidelines on type 2 diabetes and and chronic coronary heart disease do not sufficiently offer best estimates of absolute effect sizes for benefits and harms.
‘This makes it difficult for physicians to deviate from their recommendations where this is appropriate and to discuss with their patients whether a treatment option meets their individual goals and preferences.’
The team called on guideline committees to change from their rigid approach to offering ‘supportive decision aids’.
Dr Samuel Finnikin a GP in Sutton Coldfield and research fellow at the University of Birmingham who has previously worked on a NICE collaborative for shared decision making, said it was a critical issue, of which the guideline body was aware.
He said: ‘One of the key aspects of shared decision making, which should be the default method of medical decision making in my opinion, is a discussion about the pros and cons of all the options.
‘If the evidence is out there that helps us quantify the benefits then they are really crucial bits of information for helping doctors and patients make decisions.
‘It is not simply ok for guidelines to make recommendations without including some information about why that is the recommendation – including effect size, the strength of the evidence and the degree of certainty.’
Dr Margaret McCartney, a GP in Glasgow and vocal champion of evidence-based medicine, said effect sizes were essential pieces of information.
She said: ‘Guidelines can be useful – but only if there is enough nuance and detail to help make individualised and careful decisions rather than subjecting patients to an industrial tick-box exercise.’
Earlier this year the NHS unveiled a £9m programme to identify patients on GP lists at risk of a stroke because they are not on recommended medication for atrial fibrillation.
The programme was part of the NHS long-term plan’s goal to prevent more than 150,000 heart attacks, strokes and dementia cases over the next 10 years.