In recent years, more and more research has been devoted to understanding the “patient experience.” The medical world is increasingly recognizing the value of qualitative responses to prescribed forms of treatment.
Virtually all scientific disciplines have the tendency to become too heavily focused on numbers, figures, and statistics. This is no different in medicine; we sometimes acquire tunnel vision when it comes to endpoints and clinical outcomes. However, we must never forget that our patients are living, breathing human beings quite capable of pain—physical, indeed, but also mental and emotional.
The shift towards quantifying the qualitative experiences of patients has resulted in a number of new quality of life (QoL) questionnaires being developed for various diseases. These questionnaires help physicians understand the toll that an illness is having on a particular patient, as well as the impact of unwanted treatment side effects.
In line with this paradigm shift, visual analog scales have been developed to assess the symptoms of a number of chronic, progressive illnesses. In this article, we will explore the use of visual analog scales for assessing the experience of patients with idiopathic pulmonary fibrosis (IPF).
The Value of Visual Analog Scales
First, let’s take a look at what visual analog scales are. Sung and Wu characterized the development of visual analog scales as a response to the inadequacy of existing Likert-type scales. Likert-type scales, they explained, typically have a few response categories for participants to choose from that best reflect their experience. However, these scales have significant limitations, among them the fact that their design can sometimes prevent the accurate identification of respondents’ latent traits.
Visual analog scales can address some of these limitations. For example, they usually present choices on a horizontal line stretching between 2 extremes. This allows participants to grade their responses anywhere along the horizontal line, meaning that artificial boundaries and categories can be avoided. In addition, “visual analog scales are easy to understand, administer, and score, especially when the visual analog scale is implemented with a computer,” Sung and Wu wrote.
The simplicity of visual analog scales makes them ideal for measuring intangible quantities, such as anxiety, pain, and quality of life. They have been used for this very purpose rather successfully since they were developed in the 1920s. After all, the very definition of pain provided by Heller and colleagues as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” implicitly suggests that a sliding scale, and not checkboxes one can tick off, is best suited to capture the range of human emotional experiences.
Much has been written on the value of visual analog scales in various diseases and conditions, and suffice to say they have generally been praised for their ability to capture nuanced emotions and responses that may be difficult to do under different settings. Granted, visual analog scales are more appropriate in certain circumstances compared to others. Let us now look at a study analyzing the effectiveness of visual analog scales in mapping out the IPF patient experience.
Assessing the IPF Patient Experience
In a letter to the editor of the European Respiratory Journal, Moor and colleagues reported on a study they conducted in which a visual analog scale was used as part of a 24-week multicenter randomized controlled trial on the home monitoring of patients with IPF. The research team chose to use a visual analog scale due to the perceived shortcomings of patient-reported outcome measures (PROMs), which was the primary way patients with IPF reported their qualitative experiences.
Read more about IPF etiology
On the limitations of PROMs, Moor et al wrote, “PROMs are often lengthy, on paper, and with difficult scoring systems, hampering direct use in clinical practice. Thus, there is a need for easy-to-use PROMs in IPF and other interstitial lung diseases (ILDs), both for clinical trials and daily practice.”
The research team hence recruited adult patients with a diagnosis of IPF who were about to be started on antifibrotic medication. In conjunction with the visual analog scale, participants were periodically tested for their pulmonary function. Participants were randomized into 2 groups: the first was home monitored and completed weekly visual analog scores while the second received standard care and completed the visual analog scores at baseline, week 12, and week 24.
On the design of the visual analog score, Moor and colleagues wrote, “This study included visual analog scores on dyspnea, fatigue, cough, and general well-being on a continuous scale with numeric markings from 0–10 and description at both ends, with a recall period of 1 week.”
Read more about IPF patient education
Note that the questions on the visual analog scores were on responses that are deemed to be objective by some physicians. (For example, physicians often ask about dyspnea as a yes-or-no question.) The results of the study provided a fascinating, detailed look into the qualitative patient experience when suffering from IPF. The research team concluded that the scale they produced was valid and reliable to assess symptoms over a period of time.
So where do we go from here? Certainly, the patient experience should continue to feature front and center in clinical practice and research. The mountain of evidence suggesting that visual analog scale results are reproducible and reliable should prompt physicians to consider how they too can adopt this questionnaire into their practice to maximize patient well-being.
Moor CC, Mostard RLM, Grutters JC, Bresser P, Wijsenbeek MS. The use of online visual analogue scales in idiopathic pulmonary fibrosis. Eur Respir J. 2022;59(1):2101531. doi:10.1183/13993003.01531-2021
Sung YT, Wu JS. The visual analogue scale for rating, ranking and paired-comparison (VAS-RRP): a new technique for psychological measurement. Behav Res Methods. 2018;50(4):1694-1715. doi:10.3758/s13428-018-1041-8
Heller GZ, Manuguerra M, Chow R. How to analyze the visual analogue scale: myths, truths and clinical relevance. Scand J Pain. 2016;13:67-75. doi:10.1016/j.sjpain.2016.06.012