OBJECTIVES: To review publications comparing visual analogue scale data collected using 10 cm scales on paper (pVAS) and scales of various lengths in electronic formats (eVAS).

METHODS: An informal literature search for evaluation studies was conducted (search terms: “visual analogue scale” and “equivalence” or “validation”). Combined with previously-identified publications, the results and conclusions of these studies were summarised qualitatively.

RESULTS: Nineteen published studies were included. All studies were crossover comparisons of paper to at least one form of electronic data collection. Studies varied in size from 12 to 355 subjects (median: 65 subjects) and included general population volunteers and patients suffering from chronic pain, rheumatoid arthritis, psoriatic arthritis, non-small cell lung cancer, and multiple sclerosis. VAS items included measures of pain, fatigue, global health, appetite, anxiety, and alcohol effects. One study was performed in 8 to 10 year olds, the remainder in adults (18 to 86 years). Electronic modes included: PDA (n=8), PC (n=5), smartphone (n=3), tablet (n=3), feature-phone (n=2), and smartwatch (n=1). eVAS length was not reported for 5 studies, and ranged from 2 to 4 cm (n=3, min: 2.1 cm), 4.1 to 6 cm (n=5), 6.1 to 8 cm (n=3), 8.1 to 10 cm (n=2), > 10 cm (n=2, max: 28.9 cm) in the remainder. Authors of all studies concluded pVAS and eVAS were comparable. However, 2 studies reported trends towards higher scores on eVAS vs. pVAS, 3 towards lower scores on eVAS, and 2 studies (Apple Newton and Palm device) indicated eVAS scores may be lower than pVAS at the scale ends. A later study reported no scale-end effects. Differences between eVAS and pVAS were considered not clinically relevant although three publications recommended paper and electronic versions should not be used interchangeably.

CONCLUSIONS: Published evidence supports the comparability of eVAS and pVAS independent of physical eVAS length.