Phase-IV research: specifics, objectives and methodology.

The development of therapeutics is a step-by-step process. The laboratory phase O is followed by the preclinical phase the hypothesis generating phase II, the hypothesis testing phase III, and the routine treatment phase IV. Each of these treatment development and evaluation phases has its own specifics, objectives and methodologies. Phase IV comprises all scientific efforts to enhance the knowledge about a given therapy under routine treatment conditions. In phase IV the final test is done on security, effectiveness and feasibility of a treatment. Research with and on practitioners needs special non-reactive research designs.