Us­ing the terms “low-risk” or “high-risk” are of­ten dif­fi­cult to in­ter­pret.

Re­cent­ly, I high­light­ed the im­por­tance of be­ing ad­e­quate­ly in­formed be­fore con­sent­ing to a med­ical pro­ce­dure or in­ter­ven­tion. You, the pa­tient, should be at the cen­tre of any de­ci­sion-mak­ing process and it is your doc­tor’s du­ty to pro­vide the facts rather than dic­tate treat­ment.

Very of­ten, the main fac­tor in de­cid­ing on an in­ter­ven­tion such as surgery is de­ter­min­ing the risk in­volved. And your un­der­stand­ing of that risk is heav­i­ly de­pen­dant on how it is pre­sent­ed and ex­plained to you.

Af­ter all, what is risk? Risk can be thought of as the chance that any­thing could oc­cur and cause you harm. Al­most every­thing we do in our dai­ly lives car­ry some de­gree of risk. Life it­self is a risky busi­ness.

Most peo­ple will gen­er­al­ly take a risk if they feel that there is a ben­e­fit or ad­van­tage. Ide­al­ly the ben­e­fit of an in­ter­ven­tion or pro­ce­dure should out­weigh the risks. There is no such thing as ze­ro risk, and how peo­ple in gen­er­al per­ceive risk is very vari­able.

For in­stance, be­fore surgery, you may be told that it is “high-risk” or “low risk”. Some­times this is dif­fi­cult to in­ter­pret and does re­quire some form of ex­pla­na­tion or quan­tifi­ca­tion. The risks of the pro­posed surgery and the chance of com­pli­ca­tions should be pre­sent­ed in a way that is eas­i­ly un­der­stood. This can of­ten be sep­a­rat­ed in­to:

- Fre­quent risks

- Se­ri­ous risks

- Un­avoid­able risks, and each should be dis­cussed in de­tail.

In some cas­es, this may be bet­ter ex­pressed by us­ing a fig­ure such as a fre­quen­cy. For ex­am­ple, a ver­bal de­scrip­tion of “very com­mon” is usu­al­ly equiv­a­lent to a risk of 1 in 1 or 1 in 10, while “rare” could mean 1 in 1,000 to 1 in 10,000 and “very rare” is less than 1 in 10,000.

Health­care pro­fes­sion­als should use ro­bust re­search ev­i­dence to ad­vise on these risks. Usu­al­ly this is done in the con­text of an en­tire pop­u­la­tion and this may be chal­leng­ing for sev­er­al rea­sons. Your doc­tor may say to you that one in 9 women will be af­fect­ed by breast can­cer but can­not tell you if that “one” will be you.

Sim­i­lar­ly, the risk of get­ting a wound in­fec­tion af­ter a hys­terec­to­my is about 10 per cent, but that fig­ure may re­flect a gen­er­alised, pop­u­la­tion-based find­ing and may not at all re­flect an in­di­vid­ual sur­geon’s or hos­pi­tal’s fig­ures which can vary due to sub­tle dif­fer­ences in prac­tice.

There­fore, if pa­tients are to be quot­ed ac­cu­rate rates of spe­cif­ic com­pli­ca­tions, this should ide­al­ly come from the sur­geon’s own fig­ures or that of their de­part­ment rather than the en­tire pop­u­la­tion. My rate of wound in­fec­tion for the women who I op­er­ate on may in­deed be dif­fer­ent from an­oth­er sur­geon as a re­sult of vari­a­tions, such as use of an­tibi­otics, rig­or­ous clean­li­ness, hand­wash­ing prac­tices etc.

Con­se­quent­ly, it is im­per­a­tive for doc­tors to give their pa­tients an ac­cu­rate de­scrip­tion of their own com­pli­ca­tion rates. This can on­ly be done by au­dit­ing their own prac­tice to de­tect de­fi­cien­cies and make changes to im­prove them.

How risk is pre­sent­ed to us can al­so be mis­lead­ing. The 1995 “pill scare” shows how risk was tak­en out of con­text and re­port­ed in a dis­tort­ed and con­fus­ing way. At that time, it was re­port­ed that some birth con­trol pills dou­bled the risk of a de­vel­op­ing a blood clot (throm­boem­bolism) when com­pared to oth­er birth con­trol pills.

This caused pan­ic in the me­dia as well as the pub­lic with many women stop­ping their pills. Af­ter all, say­ing that some­thing “dou­bles” give the im­pres­sion of a large amount. What the re­port ini­tial­ly failed to men­tion though was that the risks of a clot with the con­tra­cep­tive pill were on­ly 1 in 6,000 to be­gin with which is con­sid­ered to be “rare”. The new re­port­ed risk was 1 in 3000 (or 2 in 6,000)—still “rare” with the in­crease be­ing about one per­son in a mil­lion. This risk had not been put in­to con­text and there­fore led to a fair amount of mis­un­der­stand­ing.

In the end, it is cru­cial to have the facts ex­plained in a mean­ing­ful way, not just to en­able you to con­sent in an in­formed way to a med­ical pro­ce­dure, but to be ful­ly aware of po­ten­tial risks in­volved. Defin­ing that lev­el of risk in the best pos­si­ble way al­lows you to have more re­al­is­tic ex­pec­ta­tions and a greater un­der­stand­ing and agree­ment be­tween you and your doc­tor.