Based on an analysis of questionnaires filled in by 2000 of the 2300 participants at John Wimber's November 1985 Harrogate Conference, followed up with later checks and consultations with doctors, this provides statistical sociological data on healings and associated phenomena experienced at the conference. It seeks to bring scientific detachment to bear on what is always an emtional subject. David Lewis concludes that genuine healing does occur - but less often than claimed - and that it is sometimes partly attributable to natural healing factors. A fellow of the Royal Anthropological Institute, David Lewis contributed an appendix to John Wimber's "Power Healing" detailing preliminary research.
I read sections of this book a few years back. Lately I read it again from cover to cover.
David Lewis took detailed surveys and follow-up data from Charismatic Christians who attended a John Wimber conference in the UK. He provides taxonomies of participants by social class, age, gender, denomination, etc., while informing us on important questions like: Who is most likely to be healed? Or what are the psychological and phenomenological correlates of receiving "words of knowledge." I have found it surprisingly difficult to uncover data like this for Pentecostals and Charismatics.
He also offers theological reflections on these phenomena, which are in congruence with what other folks have written (e.g., John White, Francis MacNutt, John Wimber)