Researchers attempting to investigate a rise in prescriptions for asthma medication have suggested that ‘poor quality’ public sector data could limit the effectiveness of new technologies and health policies.

Data science firm Polymatica sought to use NHS Digital’s GP practice data to pinpoint the cause of a 17% rise in medications prescribed for asthma between 2011 and 2017.

The data shows that the amount of asthma medication prescribed last year hit 54.6m items, up from 46.5m in 2011.

But Polymatica claimed that when it tried to find potential links between the rise in prescriptions and external factors, it was unable to draw any conclusions due to the “poor quality” of NHS Digital’s information.

Mark Hinds, CEO of Polymatica, said: “We wanted to see if external factors such as socioeconomic status or pollution would affect the level of prescriptions. But the data left us questioning whether the infrastructure and processes in place for data entry and management are up to standard.

“The government is clearly willing to make changes to public health policy – but what are they basing these decisions on? You need clean data to understand the root cause of problems like rising asthma medication.”

According to Polymatica, the main issues stemmed from the fact that data was entered manually. Because of this, addresses were often entered incorrectly, contained spelling errors and used various abbreviations that made the data difficult to aggregate.

“Ultimately, poor data quality harms results and creates inconsistent insights,” said Hinds.

“The consequences for this could be sizeable – impacting policy decisions based on data analysis and limiting the effectiveness of new technologies such as artificial intelligence.”

Not designed for analytics

The dataset used for analysis consisted of more than 700m rows of information on prescriptions written in England between 2011 and 2017.

Its primary purpose is to ensure the reimbursement of pharmacists and dispensing doctors in the NHS, Chris Roebuck, chief statistician at NHS Digital, told Digital Health News.

Roebuck acknowledged that there were some “data quality issues” in the data that could “limit some secondary analysis of it.”

He said: “It is positive that open data such as this is being used for secondary purposes by third party organisations. But it is important to understand that there are times when those undertaking such secondary analysis will encounter limitations because the dataset wasn’t designed for the purpose they are seeking to use it for.”

Roebuck also argued that the dataset used by Polymatica did not contain all the information necessary to draw the conclusions it was seeking.

“Since drugs can be prescribed to treat more than one condition, it may not be possible to separate the different conditions for which a drug may have been prescribed,” said Roebuck.

“For example, [Polymatica] may have looked at medicines that can be used to treat a range of respiratory conditions and not solely asthma.”

Despite this, Hinds suggested that better quality open data could offer “a genuine opportunity for third parties to support the NHS in helping make the nation healthier”.

He told Digital Health News: “With government funding and additional support from business, good quality open data could play an enormous role in driving initiatives such as highlighting the impact of emissions on our health and helping to put policies in place.

“With the likes of the British National Formulary, the NHS has already taken a positive step to ensure good data quality and with further investment, open data could be a powerful tool in helping to proactively identify causes of illness, reducing the burden on the NHS in the process.”