Department of Statistics

Case study: Helping patients sleep more easily

When Fisher & Paykel Healthcare wanted to do some research with sleep apnoea patients, the company sought advice from Avinesh Pillai of the Statistical Consulting Centre (SCC).

To combat sleep apnoea, a disorder characterised by airway collapse resulting in pauses in breathing while asleep which leads to fatigue, F&P’s continuous positive airway pressure (CPAP) device delivers continuously pressured, warmed and humidified air through a mask, a form of treatment considered highly effective.

But this treatment can cause problems such as a stuffy nose and dry airways, says Jen Schicker, F&P Healthcare clinical research associate, “and this discomfort is one of the leading reasons patients stop using the treatment. Ideally you use it all night, every night, to get uninterrupted sleep.”

F&P Healthcare, keen to generate robust marketing claims, wanted to set up a clinical trial to test if a CPAP with and without warmed and humidified air resulted in differences in patient compliance to therapy.

The company also wanted to do a sub-analysis of certain higher-risk apnoea patients – often those who are older and/or on certain medication – to help healthcare providers target those who would benefit most from its CPAP with humidification.
Avinesh was asked to help determine how many participants were needed to ensure statistically solid results, and provided an Excel sample size calculator F&P could use.

Avinesh says he enjoyed knowing that that his contribution “was trying to make a difference to the lives of people with sleep apnoea – well, their nasal symptoms, anyway”.