PT  - JOURNAL ARTICLE
AU  - Jonathan R Olsen
AU  - John Gallacher
AU  - Vincent Piguet
AU  - Nick A Francis
TI  - Development and validation of the Molluscum Contagiosum Diagnostic Tool for Parents: diagnostic accuracy study in primary care
AID  - 10.3399/bjgp14X680941
DP  - 2014 Aug 01
TA  - British Journal of General Practice
PG  - e471--e476
VI  - 64
IP  - 625
4099  - http://bjgp.org/content/64/625/e471.short
4100  - http://bjgp.org/content/64/625/e471.full
SO  - Br J Gen Pract2014 Aug 01; 64
AB  - Background Molluscum contagiosum (MC) is diagnosed by its distinct appearance. Parental diagnosis of MC may reduce anxiety and lead to reductions in healthcare consultations, and may be particularly useful in large-scale epidemiological studies. However, there are currently no published, validated tools allowing parental diagnosis of MC.Aim To develop and validate a tool for parental diagnosis of MC.Design and setting The Molluscum Contagiosum Diagnostic Tool for Parents (MCDTP) was developed and its diagnostic accuracy was compared with GP diagnosis in 12 GP surgeries in South Wales.Method Following development, which involved three phases with dermatologists, nurses, GPs, and parents, parents completed the MCDTP (index test) in the practice waiting room, and rated their confidence in their diagnosis. A GP then examined their child for MC (reference test). Test characteristics were calculated for all responders and for those who expressed being confident or very confident in their diagnosis.Results A total of 203 parents completed the MCDTP. The MCDTP showed a sensitivity of 91.5% (95% confidence intervals (CI) = 81.3 to 97.2) and a specificity of 88.2% (95% CI = 81.8 to 93.0) in all parents and a sensitivity of 95.8% (95% CI = 85.7 to 99.5) and a specificity of 90.9% (95% CI = 83.9 to 95.6) in parents who were confident or very confident in their diagnosis. The positive predictive value was 76.1% (95% CI = 64.5 to 85.4) and negative predictive value was 96.2% (95% CI = 91.4 to 98.8) for all parents.Conclusion The MCDTP performed well compared with GP diagnosis and is suitable for clinical use by parents and in population-based studies.