Quantitative and Qualitative Research in the Field of 'Spirituality and Health': An Introductory How-to-Guide from a Brazilian Perspective.

The present article aims to describe the different steps on how to design, develop and conduct quantitative and qualitative Spirituality and Health (S/H) studies from a Brazilian perspective, discussing definitions and instruments, and proposing a "how-to guide" for those interested in this field of research. A narrative review of the literature has been conducted by experts in the field of S/H aiming to develop a "how-to-guide". Spirituality is a very complex concept that has several challenges in the current scientific literature, including the lack of consensus in the definitions, the numerous dimensions assessed, the diverse instruments for measurement, the criticisms from other scholars, the great diversity of religious and cultural traditions and the growing number of "spiritual but not religious" individuals. This review supports that S/H studies may follow the high scientific standards, using consolidated research procedures and solid methods for both qualitative and quantitative research. Some peculiarities of the research methods for this field are discussed. S/H research is still under development, and there are several future directions for S/H studies, aiming to minimize previous criticisms and generating stronger evidence.