We release a new version of QRISK®2 every April.
Annual updates are required because of:
These factors require us to remodel the QRISK®2 algorithm to the latest version of the QResearch® database each year to ensure the algorithm keeps up to date. If the algorithm is not re-calculated, then its performance would gradually decay and its clinical value would diminish as a result. We have therefore re-fitted the algorithm using a three quarter random sample of the QResearch® practices and incorporated this into the annual update of the software.
We updated the coefficients for the QRISK®2-2016 algorithm using the latest version of the QResearch® database available at the time. The annual update documentation linked from the 2016 part of the site shows details of how risk factor recording and CVD incidence rates have changed over time.
In summary, CVD rates are declining and there has been a marked improvement in recording of self-assigned ethnicity over time.
The improvement in recording of ethnicity has resulted in more accurate estimation of risk for the different ethnic groups as it's based on a much larger sample size. The practical result is an increase in the weighting applied to the non-white ethnic groups which will result in a small increase to the corresponding risk scores.
As with any re-calibration, there are other changes to the relative risks given to the various input parameters. This is just what happens when a model is fitted to new data.
That's just fine. QRISK®2-2015 works very well. We recommend that those who integrate QRISK®2 into their own systems move to the 2016 score by the autumn -- this means that they have the freedom to schedule the work needed into a convenient point of their release cycle.