Defining Feasibility and Pilot Studies in Preparation for Randomised Controlled Trials: Development of a Conceptual Framework

We describe a framework for defining pilot and feasibility studies focusing on studies conducted in preparation for a randomised controlled trial. To develop the framework, we undertook a Delphi survey; ran an open meeting at a trial methodology conference; conducted a review of definitions outside the health research context; consulted experts at an international consensus meeting; and reviewed 27 empirical pilot or feasibility studies. We initially adopted mutually exclusive definitions of pilot and feasibility studies. However, some Delphi survey respondents and the majority of open meeting attendees disagreed with the idea of mutually exclusive definitions. Their viewpoint was supported by definitions outside the health research context, the use of the terms ‘pilot’ and ‘feasibility’ in the literature, and participants at the international consensus meeting. In our framework, pilot studies are a subset of feasibility studies, rather than the two being mutually exclusive. A feasibility study asks whether something can be done, should we proceed with it, and if so, how. A pilot study asks the same questions but also has a specific design feature: in a pilot study a future study, or part of a future study, is conducted on a smaller scale. We suggest that to facilitate their identification, these studies should be clearly identified using the terms ‘feasibility’ or ‘pilot’ as appropriate. This should include feasibility studies that are largely qualitative; we found these difficult to identify in electronic searches because researchers rarely used the term ‘feasibility’ in the title or abstract of such studies. Investigators should also report appropriate objectives and methods related to feasibility; and give clear confirmation that their study is in preparation for a future randomised controlled trial designed to assess the effect of an intervention

Comparação de inibições medulares entre indivíduos com doença de Parkinson e saudáveis

O objetivo do presente estudo foi comparar os níveis de inibição pré-sináptica (IPS) e inibição recíproca (IR) entre indivíduos com Doença de Parkinson e saudáveis e, a correlação entre essas inibições e a rigidez muscular e a severidade clínica de indivíduos com Doença de Parkinson (avaliadas através da Escala Unificada de Avaliação da Doença de Parkinson). Foram avaliados 11 indivíduos nos estágios 2 e 3 da doença e 13 indivíduos saudáveis pareados pela idade. A IPS foi menor em indivíduos com Doença de Parkinson (31,6%) do que em saudáveis (67,1%) (p = 0,02). A IR não diferiu entre indivíduos com Doença de Parkinson (26,9%) e saudáveis (27,6%) (p = 0,91). Adicionalmente, não foram detectadas correlações entre os níveis de IPS com a rigidez e a severidade clínica (p > 0,05). Portanto, mecanismos inibitórios não explicam totalmente a rigidez muscular e a severidade clinica da doença. Alterações entre ativação de músculos agonistas e antagonistas parecem estar relacionadas a influências supraespinhais anormais nos mecanismos espinhais decorrentes da doença