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. 2014 Aug 28;4(8):e005809.
doi: 10.1136/bmjopen-2014-005809.

The Performance of Seven QPrediction Risk Scores in an Independent External Sample of Patients From General Practice: A Validation Study

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Free PMC article

The Performance of Seven QPrediction Risk Scores in an Independent External Sample of Patients From General Practice: A Validation Study

Julia Hippisley-Cox et al. BMJ Open. .
Free PMC article

Abstract

Objectives: To validate the performance of a set of risk prediction algorithms developed using the QResearch database, in an independent sample from general practices contributing to the Clinical Research Data Link (CPRD).

Setting: Prospective open cohort study using practices contributing to the CPRD database and practices contributing to the QResearch database.

Participants: The CPRD validation cohort consisted of 3.3 million patients, aged 25-99 years registered at 357 general practices between 1 Jan 1998 and 31 July 2012. The validation statistics for QResearch were obtained from the original published papers which used a one-third sample of practices separate to those used to derive the score. A cohort from QResearch was used to compare incidence rates and baseline characteristics and consisted of 6.8 million patients from 753 practices registered between 1 Jan 1998 and until 31 July 2013.

Outcome measures: Incident events relating to seven different risk prediction scores: QRISK2 (cardiovascular disease); QStroke (ischaemic stroke); QDiabetes (type 2 diabetes); QFracture (osteoporotic fracture and hip fracture); QKidney (moderate and severe kidney failure); QThrombosis (venous thromboembolism); QBleed (intracranial bleed and upper gastrointestinal haemorrhage). Measures of discrimination and calibration were calculated.

Results: Overall, the baseline characteristics of the CPRD and QResearch cohorts were similar though QResearch had higher recording levels for ethnicity and family history. The validation statistics for each of the risk prediction scores were very similar in the CPRD cohort compared with the published results from QResearch validation cohorts. For example, in women, the QDiabetes algorithm explained 50% of the variation within CPRD compared with 51% on QResearch and the receiver operator curve value was 0.85 on both databases. The scores were well calibrated in CPRD.

Conclusions: Each of the algorithms performed practically as well in the external independent CPRD validation cohorts as they had in the original published QResearch validation cohorts.

Keywords: Cprd; Prognosis; Qresearch; Qrisk2; Validation.

Figures

Figure 1
Figure 1
Calibration of each QPrediction score comparing the mean predicted risks with the observed risks in the CPRD cohort. (A) QThrombosis (venous thromboembolism). (B) QFracture (hip). (C) QFracture (hip, colles, spine, shoulder). (D) QStroke (ischaemic stroke). (E) QDiabetes (type 2 diabetes). (F) QBleed (upper gastrointestinal haemorrhage). (G) QBleed (intracranial haemorrhage). (H) QKidney (moderate or severe kidney failure). (I) QKidney (severe kidney failure). (J) QRisk2 (cardiovascular disease). CPRD, Clinical Research Data Link; CKD, chronic kidney disease; CVD, cardiovascular disease.
Figure 1
Figure 1
(Continued)

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References

    1. Hippisley-Cox J, Coupland C, Vinogradova Y, et al. Predicting cardiovascular risk in England and Wales: prospective derivation and validation of QRISK2. BMJ 2008;336:1475–82 - PMC - PubMed
    1. Hippisley-Cox J, Coupland C, Brindle P. Derivation and validation of QStroke score for predicting risk of ischaemic stroke in primary care and comparison with other risk scores: a prospective open cohort study. BMJ 2013;346:f2573 - PMC - PubMed
    1. Hippisley-Cox J, Coupland C, Robson J, et al. Predicting risk of type 2 diabetes in England and Wales: prospective derivation and validation of QDScore. BMJ 2009;338:b880. - PMC - PubMed
    1. Hippisley-Cox J, Coupland C. Predicting risk of osteoporotic fracture in men and women in England and Wales: prospective derivation and validation of QFracture scores. BMJ 2009;339:b4229. - PMC - PubMed
    1. Hippisley-Cox J, Coupland C. Predicting the risk of chronic kidney disease in men and women in England and Wales: prospective derivation and external validation of the QKidney(R) scores. BMC Fam Pract 2010;11:49. - PMC - PubMed

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