This is a measure of people newly started on bisphosphonates as a proportion of ACC fracture claims. Bisphosphonates are a class of drugs that reduce bone density loss. Bisphosphonates should be considered for people who have fallen and sustained a fracture, to reduce their future risk of fracture. ‘New starts’ identifies people who were not covered by bisphosphonates in the previous 2 years.
Sub-analysis is available using the following filters:
Te Whatu Ora district
ethnicity (Māori, Pacific, Asian and Other [including unknown]).
Numerator
The number of people newly started on bisphosphonates.
A new start is defined as when a bisphosphonate was dispensed to person who was not covered by a bisphosphonate in the previous 2 years. Two years is the recommended duration for a drug holiday from bisphosphonates.
Calculating coverage Different bisphosphonate drugs have different dosing intervals. For example, zoledronic acid is typically administered annually. To account for this, the median gap between dispensations for each person and each bisphosphonate chemical ID was calculated. This median was calculated from all bisphosphonates dispensed between 2011 and 2017 to the population aged ≥50 years. Then, for each person, coverage was approximated by adding the drug’s median dispense gap to the date that the drug was dispensed for that person. For example, if a person was dispensed zoledronic acid on 1 January 2017, they were covered for 400 days (the median dispense interval for zoledronic acid), until 5 February 2018.
Denominator
The number of ACC claims for a fracture.
Denominator detail
All bisphosphonates dispensed (chemical IDs: 1037, 3938, 4015, 3868, 3939, 6033, 1487, 3913) for people aged ≥50 years.
Denominator exclusions
This measure does not include bisphosphonates that were dispensed in hospital. Interpretation of this measure should consider local practice for bisphosphonate dispensing.
