Gary Collins (@GSCollins) of the TRIPOD Steering Group introduces the TRIPOD Statement, which provides guidance for reporting clinical prediction models.
Clinical predictions are routinely made throughout medicine and at all stages in pathways of health care and are the basis for communicating risk or prognosis to patients and therefore inform the clinical decision making process. In the diagnostic setting, predictions are (for example) made as to whether a particular disease is present informing the referral for further testing, initiate treatment or reassure patients that a serious cause for their symptoms is unlikely. In the prognostic setting, predictions can be used for planning lifestyle or therapeutic decisions based on the risk of developing a particular outcome over a time period.
The multifactorial nature of making a clinical prediction makes it difficult for doctors to simultaneously combine and weight multiple risk factors to produce a reliable and accurate estimate of risk. Furthermore, it is unsurprising that numerous studies have shown that doctors are generally poor prognosticators, as they see relatively few cases and are given to cognitive biases.
Increasingly doctors, often based on recommendations in national clinical guidelines, are using multivariable prediction models to support and guide the clinical decision making process. A clinical prediction model is a mathematical equation that relates multiple predictors for an individual to the probability (or risk) that a particular disease or condition is present or will occur in the future. Well known prediction models include the Framingham Risk score, Apgar Score, Ottawa Ankle Rules, EuroSCORE, Gail Model and the Simplified Acute Physiology Score (SAPS).