An Otago University study has found the country's most vulnerable are struggling to pay for vital medicines and are reducing their doses, not filling prescriptions and skipping meals due to the cost. It also found that many of those in the poorest communties are not aware they could get a subsidy card once they've paid for 20 prescriptions in a year, and only recently has the Ministry started a system where pharmacies can cross reference a patient's prescriptions with other pharmacies. Professor Pauline Norris is from Otago University's School of Pharmacy.