For example, offering bone densitometry to women treated with bisphosphonates has been found to be associated with a lower probability of discontinuation [35], although there is no evidence that the BMD change, if any, is directly related to anti-fracture effectiveness. Moreover, the impact of offering densitometry

may be limited, since the largest loss of patients Sepantronium to selleck chemicals treatment occurs within the first 6 months of prescription, an interval in which bone densitometry is neither recommended nor proposed. Others have suggested the utility of biochemical markers to provide patients with feedback on treatment effectiveness [36], but such markers are not determined in routine clinical practice. Improving patient communication on the importance of treatment and use of reminder systems

is clearly important. For example, Briot et al. [37] reported that osteoporotic women starting therapy with a parathyroid hormone analogue Tipifarnib clinical trial who enrolled in an education and follow-up programme could achieve 15-month persistence rates >80%. It should be noted that non-persistence, as defined in this and other studies, is not necessarily equivalent to treatment discontinuation, as patients may lapse and then resume treatment after a ‘drug holiday’ of variable duration. Given the long half-life of bisphosphonates in bone tissue, such women may continue to gain some benefit from their treatment even if they go on ‘drug holidays’. Although such behaviour was not studied in detail here and would merit evaluation in a study with considerably longer follow-up duration, it is unlikely that the differences in persistence observed in our study could be accounted

for by ‘drug holidays’, as the proportion of women who did this was relatively low and similar between the two cohorts. An important potential confounding factor in any comparison of adherence between different treatment below regimens is that patients prescribed one or other regimen may be different. Indeed, in the present study, we found, for example, that women prescribed monthly bisphosphonates tended to be younger and less likely to have already experienced an osteoporotic fracture. In contrast, they were more likely to have undergone bone densitometry. This probably relates to the fact that the women could either receive a diagnosis on the basis of BMD or on the basis of fracture. Since the proportion of women with previous fractures was lower, they were de facto more likely to have received a diagnosis on the basis of low BMD, accounting for the higher use of bone densitometry in this group. Women in the monthly group were also more frequently receiving multiple comedications, which may have been an incentive for their physicians to prescribe them less frequently administered bisphosphonates. These factors may themselves influence treatment adherence and it is important that they be taken into account in any adherence study.