Adherence with bisphosphonate therapy and change in bone mineral density among women with osteoporosis or osteopenia in clinical practice
Osteoporosis International, 08/21/2012
Weycker D et al. – Among women with osteoporosis or osteopenia in clinical practice, better adherence with bisphosphonates appears to confer tangible benefits in terms of increases in bone mineral density.Methods
- A retrospective cohort study was conducted at Henry Ford Health System (Detroit, MI, USA).
- Study subjects were women who had low BMD at the left total hip (T-score < -1.0), began oral bisphosphonate therapy, and had ≥1 BMD measurements at the left total hip ≥6 months following treatment initiation.
- Change in BMD was calculated between the most recent pretreatment scan and the first follow-up scan.
- Adherence (i.e., medication possession ratio (MPR)) was measured from therapy initiation to the first follow-up scan.
- Among 644 subjects, mean age was 66 years, pretreatment BMD was 0.73 g/cm2, and pretreatment T-score was -1.8.
- Over a mean follow-up of 27.1 months, mean MPR was 0.57 (95 % CI, 0.54 and 0.59), and mean percentage change in BMD was 1.5 % (1.1 and 1.9 %).
- Within the MPR strata (five consecutive equi-intervals, from low (0-0.19) to high (0.80-1.0)), mean change in BMD was -0.8 % (-1.6 and 0.1 %), 0.7 % (-0.3 and 1.7 %), 2.1 % (1.1 and 3.0 %), 2.1 % (1.4 and 2.9 %), and 2.9 % (2.3 and 3.5 %), respectively.
- In adjusted analyses, percentage change in BMD was higher (by 1.4-3.4 %, p < 0.05 for all) in the highest four MPR intervals, respectively, versus MPR 0-0.19.