Why do some sources cited in Couplers appear to be out-of-date?
We include references in Couplers based on the following principles: • All information in a Coupler is based on published literature. The references show that the information is from published sources; they are not an exhaustive list for a subject. • Information from older sources is continually verified in newer sources. We replace old references with new ones when the information has been confirmed by one or more newer sources. • Certain types of medical information rarely change. For example, the fact that a kidney stone can cause flank pain is indisputable, whenever the reference was made. Also, if newer studies are published but the older one is still definitive, we do not replace the reference. • Sometimes an older source is the only documentation for certain information. In cases where information from an older source is unique and deemed not to be obsolete, the older reference is left intact.
