SINGAPORE - More than one in three diabetes patients are not taking their medication regularly, a study has found.

The study by the National Healthcare Group (NHG) found that 35 per cent of patients diagnosed with diabetes between 2005 and 2010 did not commit to taking their medication.

This increases the risk of hospitalisation and means that patients have less control over their blood sugar levels, say doctors.

"This is a worrying figure that we need to change," said Dr Sun Yan, deputy director of Health Services and Outcomes Research at NHG.

Still, the figure in the NHG study is lower than the global average. According to the US National Institutes of Health's National Library of Medicine database, one in two recently diagnosed diabetes patients does not take his medication regularly.

The NHG recruited 2,463 newly diagnosed patients between 2005 and 2010 for the study and monitored them for five years each.

In the first two years of the study, researchers kept tabs on how faithfully a patient took his medication. Patients are considered "adherent" if they took 80 per cent of the medication supplied.

In following three years of the study, researchers monitored the health conditions of the patient.

The study, which was recently published in BMJ Open Diabetes Research and Care journal, found that patients with poor adherence had a 0.4 increased level of HbA1c - the main indicator used to measure blood sugar levels.

Males, Indians and patients without other long-term medical conditions such as high blood pressure and high cholesterol were among those who fared the worst when it came to taking their medication regularly.

Dr Gary Ang, associate consultant of Health Services and Outcomes Research at NHG, said: "Patients who suffer from these (long-term) conditions are often more educated on taking medications and perceive their risk as higher."

As for why patients do not take their medicine regularly, healthcare professionals cited three key reasons: a lack of understanding about the medication, an avoidance of side effects and cultural beliefs.

On cultural beliefs, for example, some patients may prefer to take supplements instead of their prescribed medication. Others may have misconceptions regarding the use of insulin and oral medication.

Ms Sandra Xu, senior pharmacist at NHG pharmacy, said cultural beliefs were hardest to tackle. "It's a personal thing and we can explain to patients but their understanding of Western medicine needs to be explored further."

Dr Ang added that "debunking these misconceptions on medications and educating patients are the next steps".