Evaluation of Smartphone Versions of VAS and NRS for Use in Adults
Condition: Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      A large number of patients experience significant pain after surgery, and more patients
      report pain after discharge from hospital than before. This issue has been observed in
      patients who receive peripheral nerve blocks, the effects of which often wear off after
      discharge. There are numerous barriers to the effective control of pain away from the direct
      supervision of medical professionals, and personalized management strategies are necessary in
      order to overcome these barriers. The first step of adequate pain management is accurate pain
      assessment. Therefore, this study aims to validate a smartphone-based pain assessment tool
      that patients can access at home.
    

Detailed description: 
      1. Purpose:

           The purpose of this study is to establish whether the Panda versions of the 100mm VAS
           (Visual Analogue Scale) and NRS-11 (Numeric Rating Scale) agree adequately with and can
           therefore be used in lieu of already validated paper versions of these scales for the
           evaluation of post-operative pain in adults. The Panda versions of the pain assessment
           scales have been condensed in size onto an iPod Touch screen but otherwise appear the
           same as traditional paper versions.

        2. Hypothesis:

           There are no significant differences in the failure rates in obtaining pain scores and
           the pain scores obtained using Panda versions of the 100mm VAS and NRS-11 compared to
           the traditional paper versions.

        3. Justification:

           The management of acute post-operative pain has a profound impact on a patient's short-
           and long-term wellbeing. Studies have shown that up to 70-80% of patients experience
           pain after surgery, with the majority reporting moderate, severe or extreme pain at some
           point. Ineffective pain management can increase the risk of venous thromboembolism,
           ischemic heart disease, pneumonia, poor wound healing , insomnia, anxiety and chronic
           post surgical pain (CPSP). The management of postoperative pain after patients leave
           hospital is especially inadequate, with more patients reporting pain after discharge
           than before. Although peripheral nerve blocks (PNB) have demonstrated benefit in
           reducing immediate/in-hospital postoperative pain compared to general anesthesia (GA),
           this benefit is not sustained after patients are discharged. In fact, more patients who
           received PNB report their pain as "severe", "excruciating" or "extreme" and seek medical
           attention after leaving hospital, than those who were under GA. The nociceptive barrage
           after the signal blockade by regional anesthesia wears off can theoretically lead to
           hyperalgesia, and the substantial increase in acute pain over a period of hours can be
           highly traumatic for patients. In order to minimize this effect, patients are often
           advised to begin the titration of their oral analgesics prior to the resolution of their
           nerve blocks, often when they do not feel much pain yet. Potential barriers encountered
           during this process can include the lack of incentive to begin analgesics in the
           presence of residual nociceptive blockade, the difficulty of titrating medications away
           from the direct supervision of medical professionals, and the fear of medication
           overdose. Therefore, detailed, easily comprehensible and patient specific pain
           management instructions need to be provided as a part of the discharge plan in order to
           facilitate patient compliance.

           The first step involves developing a practical tool that allows for the accurate and
           reliable assessment and recording of pain severity that patients can use from home. Pain
           is defined as "an unpleasant sensory and emotional experience associated with actual or
           potential tissue damage, or described in terms of such damage". It is a highly
           individual experience. Therefore, self-report is considered the gold standard for pain
           assessment, with the Verbal Rating Scale (VRS), Visual Analogue Scale (VAS) and Numeric
           Rating Scale (NRS) being the three most validated self-report scales in adults. The
           VAS-100mm is a 100mm line with the anchoring words "no pain" and "worst imaginable pain"
           at the bottom and top, respectively. The NRS-11 is a line marked with numbers from 0 to
           10 at even intervals, with the anchoring words "no pain" and "worst pain imaginable" at
           0 and 10, respectively. Digital versions of pain scales that can be downloaded onto a
           smartphone have been found to be comparable to traditional paper versions in terms of
           their ability to measure pain. In addition to being portable and accessible, the
           digitization of pain assessments have the potential to reduce human errors that could
           occur during scoring and data recording. Furthermore, there is growing evidence that
           smartphone applications (apps) have the potential to improve compliance with disease and
           medication management by motivating patients to be involved in their own care. These
           properties make them promising tools for the management of postsurgical pain at home.
           The smartphone application "Panda" (Pain Assessment using a Novel Digital Application)
           developed by the British Columbia Children's Hospital (BCCH) Pediatric Anesthesia
           Research Team (PART), includes digital versions of the Faces Pain Scale - Revised
           (FPS-R) and Color Analog Scale (CAS), and has been validated in the pediatric
           population. Because the 100mm VAS and the 11-point NRS have been studied specifically in
           adults as tools for the evaluation of postoperative pain, the app will be modified to
           include these two scales to better suit this population.

        4. Objectives:

           Panda will be compared against the traditional versions for both the NRS-11 and 100mm
           VAS to analyse the following endpoints:

             -  Agreement between the two measures - the Panda score and the "traditional" score.

             -  Practicality: difference in failure rates in obtaining pain scores from Panda
                compared with the "traditional" methods

        5. Research design:

           This is an observational, randomized, cross-over controlled, open trial.

        6. Statistical analysis:

             -  Practicality: Chi-squared tests will be used to assess the difference in failure
                rates in obtaining pain scores from Panda compared with the "traditional" methods

             -  Agreement: an interval approach described by Bland & Altman will be used to
                calculate the agreement between the the Panda scores and the 'traditional' scores.

      Sample size: There will be 2 study groups- the 100mm VAS and NRS-11 groups. Each group will
      contain 2 subgroups - ages >18 to < 60 years and ≥60 to ≤ 75 years. The required sample of 32
      patients per subgroup has been calculated on the basis of Liao's proposed sample size
      calculation for an agreement study based on the Bland-Altman interval method, setting the
      discordance rate (α) = 0.05 and the tolerance probability (β) = 80%. 160 patients will be
      recruited to allow for any unplanned gaps in data collection, patients withdrawing from the
      study and other exclusions
    

Intervention name(s): Panda; Visual Analogue Scale - Original
Intervention type(s): Device; Device
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Participants had to use versions of the scale. They were randomized to using Panda or the original version of the scales first. Scores obtained using the two versions are then compared.
Masking: None (Open Label)
Primary purpose: Supportive Care
Keywords: postoperative pain; Visual Analogue Scale; Numeric Rating Scale; Smartphone