Abstract
Objective
There is little research that characterises knee pain related information disseminated via social media. However, variances in the content and quality of such sources could compromise optimal patient care. This study explored the nature of the comments on YouTube videos related to non-specific knee pain, to determine their helpfulness to the users.
Methods
A systematic search identified 900 videos related to knee pain on the YouTube database. A total of 3537 comments from 58 videos were included in the study. A categorisation scheme was developed and 1000 randomly selected comments were analysed according to this scheme.
Results
The most common category was the users providing personal information or describing a personal situation (19%), followed by appreciation or acknowledgement of others’ inputs (17%) and asking questions (15%). Of the questions, 33% were related to seeking help in relation to a specific situation. Over 10% of the comments contained negativity or disagreement; while 4.4% of comments reported they intended to pursue an action, based on the information presented in the video and/or from user comments.
Conclusion
It was observed that individuals commenting on YouTube videos on knee pain were most often soliciting advice and information specific to their condition. The analysis of comments from the most commented videos using a keyword-based search approach suggests that the YouTube videos can be used for disseminating general advice on knee pain.
Keywords
Introduction
Osteoarthritis (OA) of the knee joint is a common degenerative condition which is highly prevalent in older adults.1,2 OA is understood as a progressive disorder which usually presents with vague symptoms of joint pain and discomfort in the early stages. Individuals with these early symptoms may either seek health advice from general practice and/or seek information online regarding their health condition. 3 In particular, exploring information online before or after approaching a healthcare practitioner is widespread.4–6
Of many online information resources, social media websites such as Twitter and Facebook reportedly serve as a platform to enhance patient awareness of disease symptoms, treatment options and prevention measures. 7 The usefulness of these has been explored from various perspectives. 8 More recently, the impact of YouTube videos in supporting health education/healthcare has been explored in sports concussion, smoking cessation, obesity and multiple sclerosis.9–12
YouTube is reportedly an effective medium for healthcare communication. 13 However, the huge volumes of information with varying quality, in addition to minimal regulation of the information, may pose a significant challenge in the provision of optimal healthcare.9–13 With little way for users to ascertain the credibility of the information presented, the comments section of YouTube videos often provides an opportunity for viewers to discuss information given in the video, in a way providing validation of videos’ utility. Accordingly, a content analysis of these comments may help to determine the impact and usefulness of the information provided by the videos.14–16
Therefore, the purpose of this study was to investigate the nature of user comments in relation to non-specific knee pain, by creating a classification scheme from the comments. This work targeted non-specific knee pain which, by and large, precedes confirmed knee osteoarthritis. 17 For the purposes of the study, ‘non-specific knee pain’ is operationally defined as pain perceived in the knee which is not due to any known cause such as ligament, meniscal or hamstring injury.
Method
Study design
A qualitative content analysis 18 was used to analyse the comments publicly available on YouTube relating to non-specific knee pain videos. Similarly to previous research on social media, 14 the data was obtained from a public forum; therefore ethics approval was not required for this study.
Data source and search strategy
A systematic search was executed on 23 November 2015 of the YouTube video-sharing website (www.youtube.com). The keywords to identify the videos were determined on 10 November 2015, using Google Trends. 19 Google Trends shows how often a particular search phrase is queried when compared to total search phrases entered worldwide, and also reports on phrases that commonly co-occur with those phrases. Terms such as ‘osteoarthritis’ ‘knee pain’ and ‘knee arthritis’ were trialled on Google Trends, which resulted in the following nine commonly used search terms: ‘knee pain’, ‘pain in knee’, ‘knee joint pain’, ‘knee cap pain’, ‘knee pain treatment’, ‘knee pain symptoms’, ‘knee pain causes’, ‘knee arthritis’ and ‘arthritis in knee’.
The links to the videos from the first five consecutive result pages for each of the nine search terms were extracted. Although it is understood that 96% of users do not scroll past the first page of the search results, 20 the extraction was extended up to five pages, to counter the potential change in ranking positions with respect to geolocation of the search. 21 Links to the videos identified by the nine search terms were exported to Microsoft Excel spreadsheet, for a step by step screening process. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram 22 was adopted and modified to suit the context of the study (video selection), by screening the title of the videos followed by the description, and then the videos.
Video selection strategy
All videos which were at least two minutes long were reviewed for their inclusion in the study. Videos pertaining to other parts of the body and/or injuries, videos in languages other than English, and those that had a specific target audience other than lay people (e.g. surgical video; video recordings of conference presentations) were excluded. Videos that had disabled commenting feature were also excluded from the study.
Videos that met the above criteria were ordered based on the number of comments received (in descending order). The top 100 commented videos were extracted and further screened by one of the investigators (PJ) who has expertise specific to the physiotherapy field. From this sample, video titles identified as relevant to the topic were included in the analysis. All comments from the included videos were then extracted on 1 December 2015 via a YouTube comment scraper website 23 and transferred to an Excel spreadsheet.
Development of categories and testing consistency
A comment may contain several sentences, and thus, present multiple categories or expressions (e.g. a question and a critique). Therefore, a three-phase iterative process was undertaken to develop and refine coding categories, and test the inter-rater consistency of the categorisation process. The inter-rater agreement was determined using Cohen’s kappa (
In the first phase, a pilot scheme of categories was developed (SM and SL) by a hybrid approach, which identified new categories in addition to previously reported coding categories. 16 The comments extracted from four randomly selected videos from the list of included videos were used in the development of the categorisation scheme. 27 The developed categories were tested on 100 comments selected randomly from the four videos. The comments were coded independently by three investigators (SM, BTRS and SL), and were then compared for agreement. The discrepancies were discussed and changes required to the list of categories were undertaken. In phase 2, another set of 100 comments from the same four videos were randomly selected and tested with two investigators (SM and AT). A new coder (AT) was introduced in this phase. Discrepancies in these coding results were discussed and a final set of categories were arrived. Subsequently, another new coder (MB) was introduced to test the consistency of the final set of categories (phase 3) with another set of 100 randomly selected comments.
Dataset and sampling
The final data analysis was completed by three independent investigators (SM, AT and MB) on a set of 1000 comments randomly selected from the pool of extracted comments. A maximum of three codes were assigned if a comment represented that many contexts. 14 Discrepancy in the results of the categorisation process was discussed among the three coders. If a consensus could not be reached, the other investigators (BTRS and SL) were approached to discuss and reach a consensus.
Quality of video content
The quality of the video content was assessed using a nine-item checklist specifically developed for this purpose, based on the suggestions from a review on quality assessment of YouTube videos. 28 Additional items identified from the Health on Net (HON) code checklist 29 were also included and a final list of items was compiled. The videos were assessed as ‘Yes’, ‘No’ and ‘Not applicable’ for each item, and an overall video quality score was calculated and expressed as a percentage measure (number of ‘Yes’/total number of items). Appendix 1 provides the details of the items assessed and the scoring system.
While assessing the quality, the videos were also classified based on the
All quality assessment of the videos was completed by one of the authors with domain knowledge (PJ). Subsequently, a volunteer (LP) with similar domain expertise completed the quality assessment for all videos to determine the reliability of the quality score. The intraclass correlation co-efficient (ICC) 30 with 2, 1 was used to determine the reliability of average quality score across the nine items. The Fleiss’s criteria as described before 31 was used to interpret the ICC values: ICC < 0.40 (poor); 0.40–0.75 (fair to good); ≥ 0.75 (excellent).
Results
A flowchart of the video selection process is shown in Figure 1. Of the 900 videos identified by the search, we selected the top 100 videos based on the number of comments received. Of these, 58 videos met the criteria for inclusion in the study. Three videos that were not in English (despite the titles being in English) were excluded and a further 39 were excluded as they were identified to be irrelevant. Four videos which were used to create the initial coding scheme were also excluded. Finally 54 videos with 3192 total comments which included 2450 base comments (top comment of the thread) and 742 replies (in response to the top-level comment) were analysed. From the 54 included videos, the maximum number of comments for the top commented video was 650, the minimum number was 11, with an average of 59 comments per video. The median number of views of the 54 included videos was 64,061.5 (maximum 2,478,061; minimum 1300).
Flowchart of the video selection process.
The listing category of the included videos, according to YouTube’s classification were:
Consistency and development of categories
Final categories scheme with examples.
Categorisation of comments
Number of codes assigned to each category and their respective percentages.
Breakdown of codes assigned to subcategories under four selective categories.
Quality of video content
Quality assessment of the included videos for content and credibility.
CAM: complementary and alternative medicine; GA: general audience; HP: healthcare professional; TENS: Trans-cutaneous Electrical Nerve Stimulation; UD: unable to determine.
The breakdown of quality of the content according to Breakdown of mean video quality score according to (a) authorship (b) content suitable for. Breakdown of mean video quality score according to category of content, for videos suitable for general audience. CAM: complementary and alternative medicine.

Discussion
The primary purpose of this study was to investigate the nature of user comments on non-specific knee pain related videos, in order to understand user’s perspective of the utility of these videos. It is understood that the commenting feature of YouTube provides a space that users find beneficial to discuss individual experiences (personal situations), ask questions, offer suggestions, express approval or disapproval and affirm positive actions. It was found that in 19% of the comments, users had provided their personal situation and in 15% of the comments, questions have been asked with regard to the video and/or with respect to their personal situation. While more than a quarter (26%) of the comments had provided feedback on the videos, only 6% of those were identified to be a negative feedback or in disagreement with the video content.
User A: My damage is in the cartridge underneath the patella. Until I can do lubricating injections, will this application work, or should I use the application for patella tendonitis? User B: Thanks a lot … You turned out to be a god for me. My knee use to grind real bad. Now it has reduced …)
The
At least half of the comments in the
The key advantages of using social media in healthcare are the ease of communication of health information
7
and facilitation of a networked community to discuss, evaluate and critique health conditions.
14
In fact, in the communication process on social media a sense of community also leads to the disclosure of very personal information, towards the goal of overcoming health issues and facilitating personal actions to be taken. It was found in this study that at least 6.1% of the comments were
Overall, the significant proportion of comments identified in this study represented the
While dissemination of health care information via social media may assist with wider reach, application of the information in videos and/or any un-moderated comments has to be at an individual’s discretion, which may compromise the optimal care for their situation. The HON code suggests that online information source should explicitly state that the information is not to be considered as a replacement of care from a regular health care professional, and consumers should seek care from an appropriate health care provider. However, only seven of the included videos had incorporated this in their description and/or in the video. As the users of any online information are mostly unsure of the credibility of the information and acknowledge that there may be inaccuracies or misinformation, 32 it is imperative that the authors/sources suggest the level of use of the information provided in the video.
The major strength of this study is the rigorous process employed in developing the categories driven by the data, and testing the consistency. A sample of 1000 comments was finally analysed, with the assumption that the resultant percentages in each category would be proportional to the rest of the comments. It is not known if the analysis of all comments will have yielded different findings. This is a limitation of our study. The findings of the study are restricted to people who actively seek information online. The opinions of the videos users without an account and/or non-commenting user may yield different results. It has to be noted that these findings are derived from videos related to knee pain. Although the categories identified in this study may apply to other health conditions, the findings have to be interpreted with due caution.
Conclusion
This study provides insight into nature of users’ comments about videos on non-specific knee pain located on YouTube video sharing database. Generally, it is observed that individuals commenting on YouTube videos on knee pain were most often soliciting advice and information specific to their condition. At least 20% of the comments were complimentary of the videos, which suggests some form of usefulness of the videos.
Practical implications
The findings reported in the paper are particularly important for health professionals. The findings point to the importance of reviewing the information available on YouTube and other social media platforms, and provide appropriate directions to the patients towards use of these resources. Additionally, health professionals may support public health information by posting and sharing material (and mediating when appropriate through comments) to act as credible source of information to enhance the quality available.
The findings of this study encourage the use of YouTube as a medium for disseminating generalised healthcare education and information to lay audience. Although OA is more commonly reported in older adults, the typical onset of the disease is between 40–50 years of age, with some earlier occurrences in individuals with a previous knee injury. YouTube may be an effective medium only in the communication of general advice on prevention and monitoring strategies for knee pain. However, further longitudinal research is necessary to understand the implications of this dissemination, with a moderated comments section.
Footnotes
Acknowledgement
The authors would like to acknowledge the Summer Studentship programme of the School of Business, University of Otago, which provided a stipend to the first author of the study. The authors also acknowledge Leema Prasath (LP) for her assistance in the development of quality assessment tool and for completing the quality assessment of the videos as a second rater. The authors would like to thank the reviewers for their valuable feedback and suggestions.
Contributorship
The research question, study design and methods was developed by BTRS, SL and PJ. The data collection and extraction was done by SM. The preliminary development of categories and analysis for consistency was done by SM, SL and BTRS. Analysis of final data set (1000 comments) was done by SM, AT and MB. PJ developed the quality assessment tool for the video content, in consultation with BTRS and SL. PJ completed screening of titles for inclusion and the video quality assessment. SM prepared the first report of the research which was reviewed and commented by BTRS, SL and PJ. PJ reviewed and modified the second draft of the report, tailoring it for publication – which was further edited by other authors (BTRS, SL, AT and MB).
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Ethical approval
The study utilised the data (comments) on a public forum, voluntarily posted by the users. According to the University of Otago Human Ethics Committee’s guidelines, our study was classified as not requiring ethical approval.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Authors would like to acknowledge the Commerce Research Grant, University of Otago, which supported the quality analysis of the videos.
Guarantor
PJ
Peer review
This manuscript was reviewed by Jennifer Keelan, University of Ottawa and two others who have chosen to remain anonymous.
