[Risk analysis in surgery. A method of increasing effectiveness and efficiency: a neglected method].
The estimation of risk should be an essential prerequisite for the choice of the correct surgical therapy and also for assessment of the quality of surgical care. The fact is, that many people talk about "risk" but have the wrong idea about this remarkable concept. Too often minutely detailed enumeration of negative events (complications) is mistaken for risk. Risk is the probability that something negative will happen. It is also a fact that risk is always regarded as negative. Another fact is that risk in medicine mostly--or only--describes morbidity and mortality. Even though this is correct and important, it is not enough! Today, risk must include the probability of a therapy option not working, or even the risk of perversion of the therapy intention! Determination of a risk factor is time-consuming. It is a typical example for clinical research. Proceeding stepwise is may-be helpful. I propose seven steps: Step 1 demands that the circumstances, facts, variables like negative events, ability to cooperate, mortality, severeness of sickness, social circumstances, etc. be clarified. Step 2 means collecting and compiling these circumstances assumed to be clinically relevant All sources of information are good, but better is a prospective data collection. Step 3 defines the individual surgical situation, and from this the different circumstances, which could be risk factors. This is regarded as development of hypothesis. In step 4 the probability is determined with which a special condition or a group of circumstances could become a clinically relevant risk factor. This is done in the clinical experiment with the aid of the mathematical models known today, but also with the experience and intuition of the surgeon. In step 5 the individual clinical situation can be determined according to the significance of the risk factors (ranking). Step 6 is intended for handling the known risk factors. How to proceed with the risk factor within the decision finding process at the surgical intervention? Step 7 is the all decisive step. It should supply the unequivocal information as to whether risk analysis in toto will bring any benefit for surgery--even more importantly, for the individual patient at a certain time. There is evidence (external) that the correct handling of the risk analysis brings a significant effect or benefit in surgery, but it still has its limits. It is a fact that risk analysis with the methods used nowadays has an advantage for group analyses, but ist limits are tight for the individual patient. This is especially true for the scores established and used for this. With the risk analysis the decisive risk factors can be recognized and determined and put into order according to their different effect. Whether this fact has a benefit in surgery or even for the individual patient is still without unknown. There is evidence that comparing the quality of surgical treatments in individual clinics without risk analysis is almost naive! This is the case for which risk analysis has proved to be the best! Risk analysis is so far unable to predict the risk of a surgical therapy for an individual patient with sufficient certainty. With a value of 70% certainty, risk analysis is as good--or as bad--as the experienced surgeon for this decisive question.


CONCLUSIONS
Risk analysis has not yet given enough proof of its effectiveness. The method is time consuming and up to now only successful for assessment of groups. Comparison of surgical quality in different clinics is naive without risk analysis. Here its importance has been proved. The risk analyses practised so far have no chance when dealing with the individual patient. It can be recognized that the surgeon is a risk factor. However, in the complex system of different circumstances and mechanisms of a surgical care, he is only one factor even though an important one. Risk analysis is an aspect of clinical research and demands more consideration.
Troidl
H
H
Chirurgische Klinik Köln-Merheim.
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003362:Cost-Benefit Analysis; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011446:Prospective Studies; D011787:Quality of Health Care; D012189:Retrospective Studies; D012306:Risk; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013514:Surgical Procedures, Operative / Q000592:standards