Its all in the incentives
I chanced upon this amusing letter in TODAYonline. Haslinda Shamsudin asks:
I would like to raise a point about conflicting advice given to women. Polytechnic doctors who perform pap smear screenings would advise their patients that it is sufficient to have it done once in three years.
Gynaecologists in private practice and at government hospitals would however, advise that such screenings be done annually. Perhaps the Obstetrical and Gynaecological Society of Singapore could clear the air.
I think the answer to this curious conundrum is pretty clear: its all in the incentives. PolyCLINIC doctors are paid a flat wage rate, non-dependent on the number of procedures they perform. Thus they would try to minimise the amount of work they have to do, given that more work does not translate to more pay. More work would simply mean more hassle for them.
Conversely, gynaecologists in private practice charge by number of consultations/procedures that they do. Thus their incentives are reversed: they would try to increase the number of procedures that they can perform on you.
Of course, this does not give you an answer on what is the optimal rate of pap smears should be. Perhaps the answer is somewhere in between. Average out the answers between private and public practice gynaecologists and you get 1.5 years. Voila!
