Một số các viên thuốc được thực hiện bởi một bệnh nhân trong một thử nghiệm lâm sàng thường được sử dụng như một biện pháp tuân thủ. Phương pháp này là hết sức rõ ràng, và ngay cả khi đối tượng trả về số lượng thích hợp thuốc còn sót lại tại một chuyến thăm theo lịch trình | Drinkers Abstainers Figure 66 Examples of pie charts. Pill count A count of the tablets taken by a patient in a clinical trial that is often used as a measure of compliance. The method is far from foolproof and even when a subject returns the appropriate number of leftover pills at a scheduled visit the question of whether the remaining pills were used accordingly remains largely unanswered. There is considerable evidence that the method can be unreliable and potentially misleading. Journal of Clinical Oncology 1993 11 1189-97. Pill count The claim is often made that in published drug trials more than 90 of patients have been satisfactorily compliant with the protocol-specified dosing regimen. But some researchers have questioned such claims based as they usually are on count of returned dosing forms which patients can manipulate easily. Certainly data from more reliable methods for measuring compliance electronic monitoring chemical markers etc. contradict them. Pilot study A small-scale investigation designed either to test the feasibility of methods and procedures for later use on a large scale or to search for possible effects and associations that may be worth following up in a subsequent larger study. Pilot survey A small-scale investigation carried out before the main survey primarily to gain information and to identify problems relevant to the survey proper. Pixel A contraction of picture element . The smallest element of a graphical display. Placebo The word placebo literally I will please has been defined as an inert substance given for its psychological effect to satisfy the patient. But nowadays the term is usually used for a treatment designed to appear exactly like a comparison treatment but that is devoid of the active component. Placebo effect A well-known phenomenon in medicine in which patients given only inert substances often show subsequent clinical improvement when compared with patients not so treated . Often defined explicitly as the .
