Pharmac insists the meters have been independently tested. It advised people with concerns to contact Medsafe. "People have been using the previous meters for a long time and they trust them, which is completely understandable," said Pharmac's Simon England.
He said tests indicated CareSens devices were the most reliable. This week, Diabetes NZ president Chris Baty defended the meters. She said other strips read blood glucose levels too low, rather than CareSens devices which read them too high.
In response to a question from MP Brendan Horan in Parliament, Tony Ryall said Medsafe received three incident reports last year and 11 this year for an estimated 90,000 users of CareSens.
Nearly 3,000 people have signed an online petition against the sole-supply deal. Petition author Carrie Hetherington said her own readings were "scarily inaccurate".
Another concern relates to its use in temperatures under 10C. Horan said: "Even more unsatisfactory is the response from Pharmac, telling people to warm them up under their armpits before use."
CareSens products are distributed by Pharmaco, and spokesman David Pavey said they understood concerns. "While we acknowledge these and people's concerns, we also stand by the quality and accuracy of the CareSens meters."