RESUMO
OBJECTIVE: In this study, we aimed to assess comparative productivity of 21 pharmaceutical companies in Iran during 2000-2013. METHODS: To evaluate the productivity trend of pharmaceutical companies in Iran, we used data envelopment analysis-based Malmquist index. "Total assets" and "capital stock" as inputs and "net sales" and "net profit" as outputs extracted from Tehran stock exchange, were selected to be included in the analysis. This method provides the possibility for analyzing the performance of each company in term of productivity changes over time. We also used an estimation generalized least square panel data model to identify the factors that might affect productivity of pharmaceutical companies in Iran using EViews 7 and Deep 2.1 software. FINDINGS: The mean total productivity during all years of the study was 0.9829, which indicates the improvement in their overall productivity. The results, over the 13-year period, indicated that the range of productivity changes in pharmaceutical companies, that were included in this study, was between 0.884 and 1.098. Panel data model indicated that age of company could positively (t = 4.765978, P < 0.001) and being located in cities other than Tehran (the capital) could negatively (t = -5.369549, P < 0.001) affect the productivity of pharmaceutical companies. The analysis showed the new policy (brand-generic scheme) and also the type of ownership did not have a significant effect on the productivity of pharmaceutical companies. CONCLUSION: In this study, pharmaceutical productivity trends were fluctuated that could be due to the sub-optimal attention of policy makers and managers of pharmaceutical companies toward long-term strategic planning, focusing on productivity improvement.
RESUMO
Two decades of the amyloid-ß (Aß) hypothesis in Alzheimer's disease (AD) and the prominence of Aß-targeting strategies have yet to meet the levels of original expectation. Disappointing results in numerous Phase II/III studies have called for a re-examination of the validity of the Aß-targeting approaches as an intervention strategy in AD. The mid-life onset of chronic conditions (e.g., hypertension, diabetes, insulin intolerance, and depression nominated as risk factors for the later development of AD) points to the possibility that each condition could involve mechanisms, which while relatively modest over a short-term, could have significant accumulative effects. What may also not be fully appreciated is that a number of these conditions involve potential disturbances to multivalent cations (MC) levels through various mechanisms such as autophagy, oxidative stress, and apoptosis. Furthermore, some MCs have intimate associations with the mechanisms by which Aß pathology manifests. Considering various lines of evidence and incorporating statistical analysis on Disability-Adjusted Life Years (DALYs) data of both causes of and prevalence of multifactorial risk factors in different world regions, we propose an MC hypothesis for AD. More specifically, we suggest that MC imbalance marks many chronic conditions and because of their involvement with Aß pathology, could reflect that Aß may be a vital manifestation and marker of underlying MC imbalance. Thus, careful targeting of MC imbalance may provide an alternative or complementary interventional approach to current Aß treatment strategies.