Content Analysis of YouTube Videos on the Effect of Vitamin C on Common Cold

Donghwi Park; Sang Gyu Kwak; Saeyoon Kim; Min Cheol Chang

doi:10.4082/kjfm.23.0093

Abstract

Background

With the growth of the Internet, social media platforms have emerged as major sources of medical information. We assessed the reliability, quality, and accuracy of the most-viewed YouTube videos containing information on the effect of vitamin C on the common cold.

Methods

The YouTube videos were searched on August 1, 2022, using the keywords: (“ascorbic acid” OR “vitamin C” OR “Sodium Ascorbate” OR “L-ascorbic”) AND “common cold”. The 30 most-viewed videos were included in our study. The reliability and quality of the videos were analyzed using modified DISCERN and Global Quality Scales, respectively. When the videos included at least one correct or inaccurate scientific statement about the effect of vitamin C on the common cold, they were classified as accurate or misleading videos, respectively; those without any pertinent information were considered neither accurate nor misleading. If a video contained both accurate and inaccurate statements, it was classified as misleading.

Results

Of the 30 most-viewed videos, 73% were unreliable, and 67% contained misleading information and were of a poor quality. Of these 30 videos, 14 videos were produced and posted by customers who were not specialized in medicine or nutrition. Moreover, these videos were of significantly lower reliability, quality, and accuracy than those produced by nutrition or fitness channels or by medical or nutrition professionals.

Conclusion

The reliability, quality, and accuracy of videos uploaded by non-professionals were low. Therefore, video creators should upload reliable, high-quality videos to ensure the dissemination of accurate medical information.

Keywords: Common Cold; Vitamin C; Internet; Review; Social Media; Information

INTRODUCTION

The common cold is the most common infectious syndrome in humans. It is caused by over 200 viruses and presents with a multitude of symptoms, such as runny nose, sore throat, cough, nasal stuffiness and discharge, sneezing, and headache, with or without fever and with inter-individual variation in presentation and severity. It follows a benign course and is self-limiting in healthy individuals. However, a few complications, such as secondary bacterial infections and exacerbation of asthma or chronic obstructive pulmonary disorder, can develop [1,2]. The common cold is the leading cause of acute morbidity and economic burden to society or the country and is also a major cause of absence from school and work [3].

The common cold is still deemed incurable and is only treated symptomatically using various medications [1,2], such as antihistamines, analgesics, decongestants, antitussives, antipyretics [4,5], and other beneficial drug therapies [6,7]. Several animal studies have found that vitamin C increases resistance to viral and bacterial infections, and it was hypothesized that vitamin C would have a similar effect on humans [8-10]. In 1970, Pauling, who had won Nobel Prizes for Chemistry (1954) and Peace (1962), claimed that vitamin C prevented the occurrence of common cold and alleviated its symptoms [11]. Several clinical trials have been conducted to evaluate the antiviral effects of vitamin C. In 2013, Hemilä and Chalker [12] performed a meta-analysis of 29 placebo-controlled trials and concluded that vitamin C supplementation cannot reduce the incidence of common cold in the general population. However, vitamin C was found to reduce the duration and severity of the common cold by 7.7%, and these results have been globally accepted.

Today, people can easily obtain health information online owing to advancements in the Internet, making it the most prominent source of health information. When people have questions regarding health issues, they seek information from social media, where the opinions of several medical experts and the experience of the public are available. However, online multimedia platforms can contain inaccurate medical information, leading people to make incorrect decisions regarding health issues [13-15]. YouTube is the most popular and largest online video-sharing platform and is regarded as important for the dissemination of medical information.

This study evaluated the reliability, quality, and usefulness of the most viewed YouTube videos on the effects of vitamin C on the common cold.

METHODS

1. Video Selection

This study conducted a search on the YouTube website (https://www.youtube.com/), on August 1, 2022, using the keywords: (“ascorbic acid” OR “vitamin C” OR “Sodium Ascorbate” OR “L-ascorbic”) AND “common cold”. The inclusion criterion for the videos was content related to the effects of vitamin C on the common cold in English. Duplicate videos and videos without audio clips were excluded. The 30 most viewed videos that fulfilled this criterion were selected for this study. Ethics committee approval was not required for this study: there were no human participants, and the videos were publicly accessible.

2. Data Extraction

The data pertaining to the title; production source; duration since uploaded on YouTube; video length; and the total number of views, likes, and subscribers were extracted from each video. The video production sources were categorized as nutrition or fitness channels, television- or Internet-based news or programs, medical or nutrition professionals, consumers (individuals without any professional affiliation), and company channels or product advertisements (videos uploaded by a supplement-producing company or for the promotion of products).

3. Assessment of Reliability, Quality, and Accuracy

To assess the reliability of the video content, the modified DISCERN (mDISCERN) scale was adapted from the original DISCERN tool designed by Charnock et al. [16] and used for the assessment of written health information. The mDISCERN scale includes the following five questions: whether (1) the aims are clear and achieved, (2) reliable sources of information are used, (3) the presented information is balanced and unbiased, (4) additional sources of information are listed for patient reference, and (5) areas of uncertainty are mentioned. A higher mDISCERN score indicates greater reliability. When the mDISCERN score was ≥3, the information was considered highly reliable.

The Global Quality Scale (GQS) was used to assess the quality of the video content [17]. GQS was originally developed to evaluate websites to assess the flow and ease of use of the available information. The information can be classified by the GQS as follows: (1) poor quality, poor flow, and missing most of the information and hence, not helpful; (2) generally poor, with some information but of limited use; (3) moderate quality, and some adequately-discussed, important information; (4) good quality, good flow, and covering the most relevant information, making it useful; and (5) excellent quality and flow, making it very useful. Thus, a higher GQS score indicated greater quality.

Additionally, each video was classified as “accurate,” “misleading,” or “neither accurate nor misleading.” When the videos included at least one correct or inaccurate scientific statement about the effect of vitamin C on the common cold, they were classified as accurate and misleading, respectively; those without any pertinent information were considered neither accurate nor misleading. If a video contained both accurate and inaccurate statements, it was classified as misleading. Two reviewers (M.C.C. and D.P.) assessed the reliability, quality, and accuracy of the included videos. Discrepancies in the assessments were discussed to reach a consensus. The assessment was based on a review by Hemilä and Chalker [12].

4. Statistical Analysis

IBM SPSS ver. 25.0 (IBM Corp., Armonk, NY, USA) was used for statistical analysis. The Kruskal-Wallis and chi-square tests were used to evaluate the differences in the general features and assessment results of the videos, across the groups categorized by production source. Dunn’s test was used for multiple comparisons. The Mann-Whitney U test was used to compare videos with mDISCERN scores ≥3 and <3; videos with moderate to excellent quality (GQS ≥3) and poor quality (GQS <3); and those categorized as accurate, misleading, and neither accurate nor misleading. Statistical significance was set at P<0.05.

RESULTS

The general features (production source; duration on YouTube; video length; and total number of views, likes, and subscribers) of the 30 most viewed videos are listed in Table 1. The web addresses, titles, and other details of the YouTube videos are presented in Supplement 1. Of the 30 videos, six were produced by nutrition or fitness channels, one by television- or Internet-based news or programs, nine by medical or nutrition professionals, and 14 by customers. The average mDISCERN score of the videos analyzed was 1.2±1.8. In total, 26.7% (n=8) videos contained highly reliable information. The distribution of videos according to the mDISCERN scores was as follows: 5 points, n=3; 4 points, n=2; 3 points, n=3; 2 points, n=2; 1 point, n=1; and 0 points, n=19. Regarding the assessment of information quality, the average GQS score of the included videos was 2.2±1.7 (approximately 2 points and thus, categorized as generally poor). The quality of 10 videos (33.3%) was categorized as excellent (n=7, 23.3%) and moderate (n=3, 10%). Three videos (10.0%) were of generally poor quality and 17 (56.7%) were of poor quality. Furthermore, 10 videos (33.3%) were classified as accurate and the remaining 20 (66.7%) were classified as misleading.

Intergroup comparisons following the different production sources showed that the mDISCERN scores were significantly higher for the videos produced by nutrition or fitness channels and by medical or nutrition professionals than those produced by customers (Kruskal-Wallis test, P=0.018; nutrition or fitness channels, 2.0±1.9; medical or nutrition professionals, 2.3±2.4; customers, 0.1±0.5) (Tables 2, 3). Similarly, the GQS scores were higher for videos produced by nutrition or fitness channels and by medical or nutrition professionals than for those produced by customers (Kruskal-Wallis test, P=0.003; nutrition or fitness channels, 3.0±2.2; medical or nutrition professionals, 3.3±1.7; customers, 1.1±0.5) (Tables 2, 3). The proportion of accurate videos produced by nutrition or fitness channels and by medical or nutrition professionals was higher than that produced by customers (chi-square test, P=0.028; nutrition or fitness channels, 50%; medical or nutrition professionals, 55.6%; customers, 7.1%) (Table 2). However, there were no significant differences in other aspects, such as the duration on YouTube; video length; and the number of views, likes, and subscribers for the different production sources (Kruskal-Wallis test, P>0.05) (Table 2).

The Mann-Whitney U test of videos with mDISCERN and GQS scores ≥3 and <3 did not reveal a significant difference in the duration on YouTube (P=0.400, P=0.669), video length (P=0.975, P=0.798), number of views (P=0.400, P=0.588), number of likes (P=0.106, P=0.194), or number of subscribers (P=0.092, P=0.066). Similarly, on comparing the accurate and misleading videos, no significant differences were observed (YouTube duration, P=0.669; video length, P=0.798; number of views, P=0.588; number of likes, P=0.194; and number of subscribers, P=0.066).

DISCUSSION

This study revealed that 73% of the 30 most-viewed videos on the effects of vitamin C on common cold were unreliable. Moreover, 67% were of poor quality and contained misleading information. Therefore, it is evident that these videos had concerns with respect to their reliability, quality, and accuracy.

Further, 14 videos were produced and uploaded to the Internet by customers who did not specialize in medicine or nutrition. The average mDISCERN and GQS scores of videos produced by customers were 0.1 and 1.1, respectively, indicating the unreliability and poor quality of the video content [16,17]. In addition, most videos produced by customers contained misleading information. Despite the ineffectiveness of vitamin C in preventing the common cold and its minimal reducing effect on the duration and severity of infection, its benefits are over-exaggerated by non-professionals [12]. Non-specialized individuals need to refrain from uploading videos without sufficient knowledge of a topic, and consumers should obtain specialist opinions on the same.

In addition, even for videos uploaded by specialist channels or professionals, the average mDISCERN score was 2.0–2.3, and GQS category was of poor quality, indicating poor reliability [16]. Furthermore, approximately half of the videos contained misleading information. To create videos, professionals must thoroughly review published studies and produce factual, evidence-based videos.

However, the reliability, quality, and informational accuracy of the videos did not affect the number of likes or subscribers. This indicates the incompetence of the public in judging the precision of the information available in videos posted online, thus emphasizing the need for professionals and their societies to create high-quality videos with accurate information and actively share them on social media platforms.

Thus, the reliability, quality, and accuracy of the 30 most viewed YouTube videos, especially those posted by nonprofessionals, regarding the effects of vitamin C on the common cold were low. The importance of social media in medicine and health has recently been growing. Video creators, particularly medical professionals, should upload reliable, high-quality videos to ensure the dissemination of accurate medical information. To the best of our knowledge, this is the first study to analyze YouTube video statistics for content based on the role of vitamin C in the medical management of the common cold. However, our study was limited in that we analyzed only a small number of videos. Further studies involving a larger number of videos are required.

Notes

CONFLICT OF INTEREST

No potential conflict of interest relevant to this article was reported.

SUPPLEMENTARY MATERIALS

Supplementary materials can be found via https://doi.org/10.4082/kjfm.23.0093.

Supplement 1.

The details of the 30 most viewed videos.

kjfm-23-0093-Supplementary-1.pdf

Table 1.

General features and results of the assessment of videos

Video features	Mean±SD	Min–max
Duration on YouTube (mo)	63.2±45.9	2–175
Video length (sec)	492.3±643.2	46–3,431
No. of views	60,741.9±213,497.2	2,657–1,162,745
No. of likes	1,687.1±6,420.6	10–34,000
No. of subscribers	766,093.4±2,323,356.3	13–10,700,000
mDISCERN score	1.2±1.8	0–5
GQS score	2.2±1.7	1–5

SD, standard deviation; mDISCERN, modified DISCERN; GQS, Global Quality Scale.

Table 2.

Comparison of the assessed characteristics of the videos between the groups, classified according to production sources

Variable	1: Nutrition or fitness channels (n=6)	2: Television or Internet-based news or programs (n=1)	3: Medical or nutrition professionals (n=9)	4: Customers (n=14)	P-value
mDISCERN	2.0±1.9	2	2.3±2.4	0.1±0.5	0.018 (1,3>4)
mDISCERN	2 (0–4)	2	3 (0–5)	0 (0–2)	0.018 (1,3>4)
GQS	3.0±2.2	3	3.3±1.7	1.1±0.5	0.003 (1,3>4)
GQS	3 (1–5)	3	3 (1–5)	1 (1–3)	0.003 (1,3>4)
Accuracy					0.028 (1,3≠4)
Misleading	3 (50.0)	0	4 (44.4)	13 (92.9)
Accurate	3 (50.0)	1 (100.0)	5 (55.6)	1 (7.1)
Duration on YouTube (mo)	87.8±67.6	94	49.3±45.4	59.3±34.3	0.362
Duration on YouTube (mo)	56.5 (33–175)	94	28 (2–141)	47.5 (19–118)	0.362
Video length (sec)	186.8±98.5	136	581.6±480.9	591.2±841.4	0.067
Video length (sec)	223 (46–278)	136	484 (69–1,408)	298 (208–3,431)	0.067
Views	241,676.3±462,662.6	11,175	16,278.6±18,165.6	15,322.6±16,110.4	0.964
Views	9,706.5 (2,946–1,162,745)	11,175	9,556 (2,657–59,344)	5,531.5 (3,039–47,941)	0.964
Likes	7,209.8±13,577.4	37	305.1±306.4	221.9±288.9	0.713
Likes	213 (13–34,000)	37	189 (23–956)	120 (10–1,100)	0.713
Subscribers	3,172,833.3±4,601,811.9	138,000	192,050±316,038.3	101,020±222,924.8	0.014 (1>3>4)
Subscribers	382,000 (122,000–10,700,000)	138,000	40,700 (650–856,000)	5,920 (13–798,000)	0.014 (1>3>4)

Values are presented as mean±standard deviations, medians (minimum–maximum), or frequencies (%). P-values were obtained using the chi-square or Kruskal-Wallis test for non-parametric data. The multiple-comparisons results were obtained using the Dunn’s test. Statistically significant results are marked in bold.

mDISCERN, modified DISCERN; GQS, Global Quality Scale.

Table 3.

The number and percentage of videos in each score in mDISCERN and GQS in the groups classified according to production sources

Variable	1: Nutrition or fitness channels (n=6)	2: Television or Internet-based news or programs (n=1)	3: Medical or nutrition professionals (n=9)	4: Customers (n=14)
mDISCERN
0	1 (16.7)	0	4 (44.4)	13 (92.9)
1	1 (16.7)	0	0	0
2	1 (16.7)	1 (100.0)	0	1 (7.1)
3	1 (16.7)	0	2 (22.2)	0
4	2 (33.3)	0	0	0
5	0	0	3 (33.3)	0
GQS
1	2 (33.3)	0	1 (11.1)	13 (92.9)
2	1 (16.7)	0	3 (33.3)	0
3	0	1 (100.0)	1 (11.1)	1 (7.1)
4	0	0	0	0
5	3 (50.0)	0	4 (44.4)	0

Values are presented as frequencies (%).

mDISCERN, modified DISCERN; GQS, Global Quality Scale.

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