A total of 200 webpages were extracted from the first 5 pages of each search strategy. After screening for duplicates, 100 webpages were excluded. Of the remaining 100 webpages, 41 were excluded for the following reasons: did not sell kratom (n = 11), did not ship to Canada (n = 8), invalid URL (n = 8), e-commerce website (n = 6), not published in English (n = 3), news outlet (n = 3), a social media page (n = 1), and a Wikipedia article (n = 1). A further 8 webpages belonging to the same websites were collapsed into a single item. The remaining 51 websites were deemed eligible and assessed with the DISCERN instrument. This process is depicted in Fig. 1.
General characteristics of eligible websites
Sixty-one percent (31 out of 51) of websites exclusively sold kratom products, while 29% (15 out of 51) of websites also sold other herbal products such as cannabidiol, turmeric, and herbal teas. No websites discussed any conventional therapies, such as pharmaceutical medications or surgery. A common feature among websites were the inclusion of blogs and news sections addressing topics such as the benefits, risks, legality, user experience, and biochemical interactions of kratom. Forty-seven percent (24 out of 51) of websites stated that their kratom products were solely for research purposes, not for human consumption. The general characteristics of all eligible websites assessed using the DISCERN instrument are presented alphabetically in Table 1.
DISCERN instrument ratings
The average summed DISCERN score across all 51 websites was 36.95 (SD = 2.44) out of 75. This score is representative of the poor quality of consumer health information available on these websites. Of the first 15 questions, only question 1 (if the aims were clearly stated) and question 2 (if the aims were achieved), had a total mean score greater than 3 (out of 5) across all websites; all other questions had a total mean score of less than 2.5. DISCERN scores for each question of each website are presented in Table 2, listed in descrneding order of summed DISCERN score
Trends identified across resources assessed
SECTION 1 is the publication reliable? (questions 1–8)
Questions 1 and 2 assessed if the aims of the website were clearly stated and if those aims were achieved, respectively. The questions that received the highest total mean scores were question 1 that scored 4.16 (SD = 1.10) and question 2 that scored 4.16 (SD = 1.10). Websites with higher scores on questions 1 and 2 generally had a separate page explaining their aim which often included information about the type of product being sold, the origin of the product, and the location of the distributor. Question 3 assessed the relevance of the consumer health information present on the website. The presence of information that was relevant to different types of consumers, such as pregnant women, seniors, and adolescents, was evaluated in this question. This question received the lowest total mean score of 1.37 (SD = 0.54), with all of the websites scoring a 2.5 or less. Websites that received relatively higher scores examined some risks to different types of consumers. However, many retailers lacked a sufficient explanation of the risks of kratom to potentially at-risk consumers. These websites advised consumers to consult a healthcare provider before consuming kratom products, in cases such as when pregnant or nursing. Question 6 assessed whether the information presented on the website was balanced and unbiased. The websites received a mean score of 1.92 with 84% (43 out of 51) of them receiving an average score of less than 3. This score reflects the fact that many websites presented questionable information or promotional material on their website. Sixteen percent (8 out of 51) of websites achieved a rating of 3 or higher and used sources such as peer-reviewed literature or government websites to support their claims. Question 8 examined whether the website made mention of any uncertainties associated with the product advertised. These uncertainties pertained to a lack of research on the product, variable side effects and risks of the product, and the legality of the product. Eighty percent (41 out of 51) of the websites scored 2.5 or less on this question.
SECTION 2 how good is the quality of information on treatment choices? (questions 9–15)
Questions 10 and 11 assessed whether the website correctly identified the benefits and the risks associated with the product, respectively. Thirty-three percent (17 out of 51) of the websites achieved a rating of 3 or higher on question 10; in contrast, only 16% (8 out of 51) of the websites achieved a rating of 3 or higher on question 11. For those websites that identified the risks, they did not do so extensively and only mentioned risks specific to certain consumer populations, such as pregnant women. Otherwise, risks were stated in the form of a legal disclaimer surrounding kratom. Websites that achieved a relatively higher score on both questions 10 and 11 had a section dedicated to examining the benefits and risks of the product. Question 12 assessed whether the website described what would happen if no product was used. All websites achieved a score of 1.5 or lower, as generally minimal to no pertinent information was provided. Question 13 assessed whether the website described how the product may impact the overall quality of life. Ninety-eight percent (50 out of 51) of the websites scored 2.5 or less.
SECTION 3 overall rating of the website (question 16)
Question 16 examined the overall quality of the website as a source of information. Ninety percent (45 out of 51) of websites had an overall score of less than 3 out of 5. Of the 10% (5 out of 51) of websites with a score higher than 2, the highest score was 3.5 out of 5. The relatively low ratings can be attributed to the lack of information provided by the websites including, but not limited to: biased information, missing references, and minimal mention of uncertainties. Some of the higher scoring websites included information concerning the benefits, risks, and uncertainties associated with the product.