A longitudinal study of consistency in diagnostic accuracy of teledermatology tools.

Background: Diagnostic accuracy (DA) is an outcome measure to assess the feasibility of teledermatology tools. Despite ample data with variable DA values, no study has examined the aggregate DA value obtained from the available studies and observed its consistency over a period of time. This kind of a longitudinal study about teledermatology will be necessary to check its usefulness and plan for further implementation.

Aims: To observe the DA trend over a period of 15 years (1997-2011).

Methods: Only those studies (n = 59) using a single tool for general, tertiary, and subspecialty teledermatology practice were included to obtain the DA values. Studies were graded based on the number of subjects and gold standard comparison between teledermatologist and clinical dermatologist (face-to-face examination).

Results: This analysis sought to identify the DA trend was carried out by evaluating 17 store and forward teledermatology (SAFT) based and 8 Video conference (VC) tool-based studies with 2385 and 1305 patients respectively, in comparison with the gold-standard assessment. The average DA was 73.35% ± 14.87% for SAFT and 70.37% ± 7.01% for VC. One sample t-test analysis with 100% accuracy as standard value revealed 28% deficiency for SAFT (t = 7.925; P = 0.000) and 30% deficiency for VC (t = 11.955; P = 0.000). Kruskall-Wallis test confirmed the consistency of DA values in the SAFT (χ2 = 1.852, P = 0.763) tool.

Conclusion: SAFT and VC were adequately validated on a large number of patients by various feasibility studies with the gold standard (face-to-face) comparison between teledermatologists and clinical dermatologists. The DA of SAFT was good, stable over the 15 years and comparable to VC. Health-care providers need to plan for appropriate utility of SAFT either alone or in combination with VC to implement and deliver teledermatology care in India.