Abstract
Objective:
To assess the quality, content, and readability of information available online on vitreous floater information.
Design:
Cross-sectional study.
Participants:
Not applicable
Methods:
Websites were generated using a Google search of “vitreous floaters treatment” and “[State]” and were analyzed using a standardized checklist of 22 questions. Readability was assessed using the Flesch Reading Ease score. Websites met qualification criteria if they represented U.S. based institutions, if they provided clinical care and addressed vitreous floater treatment on their website.
Results:
Of the 1,065 websites screened, 456 were included. Of these, 406 (89%) were private institutions, 24 (5.3%) were academic, and 26 (5.7%) were a combination of private and academic. The average readability score correlated to a 10th-12th grade reading level. Vitreous floater treatment was discussed on 283 (62.1%) websites and 63 (21.8%) websites discussed potential side effects. Google rank was inversely correlated with depth of explanation (r= −0.114, p=.016). Observation was the main treatment recommended (55.8%, n=158), followed by laser treatment (27.6%, n=78), no specific treatment recommendation (11.3%, n=32), and vitrectomy (5.3%, n=15). Centers with vitreoretinal surgeons were 16.43 times more likely to recommend vitrectomy than those without vitreoretinal surgeons (p<0.001).
Conclusions:
Online information about vitreous floater treatment is variable, and the material is at a higher than recommended reading level for health information. While treatment was discussed by nearly two thirds of websites, less than a quarter mentioned possible complications, and treatment recommendations varied significantly depending on physician training.
Keywords: floaters, vitreoretinal surgery, patient education
Introduction
With the advent and popularization of the Internet, many patients first turn to the Internet for medical information before interacting with a physician.1 There is currently no standard for the quality and accuracy of health information found online, and this is potentially problematic given that the general population is not trained to differentiate peer-reviewed sources from less dependable sources. Thus, the average consumer may not be able to differentiate articles based on the quality of information.2 Due to the lack of standardization in online information quality, articles will differ in completeness, accuracy and potentially have biases. This could lead patients to be misinformed or pursue detrimental treatment options.3
For vitreous floaters, a common eye complaint with generally benign pathology and controversial therapeutic options, this issue is particularly salient. The majority of the population experiences vitreous floaters in their lifetime, including up to 76% of smartphone users.4 Vitreous floaters often occur as a result of molecular changes to the collagen extracellular matrix in the eye, and patients describe floaters as bubbles, dark spots, bugs or cobwebs in the temporal visual field.5 While vitreous floaters can occur for many reasons including inflammation, they most commonly occur due to aging.5 Objectively quantifying the severity of floaters is challenging as patients do not usually have a loss of visual acuity, although correlation with contrast sensitivity has been demonstrated.6, 7 Since the impact floaters have on a patient’s quality of life is primarily subjective, the treatment is predominantly patient-driven increasing the likelihood that patient’s will turn to the internet for information. Given the benign nature of most floaters, the most common management in the absence of retinal pathology is observation.8 When treatment is considered, options include Nd-Yag laser vitreolysis, cataract surgery combined with deep anterior vitrectomy, and pars plana vitrectomy.9
In order to better understand the influence of the Internet on patients’ treatment decision choices, it is important to qualify the reliability of information that exists currently. This study attempts to evaluate the quality of vitreous floater information presented to patients via the Internet and determine whether there are any biases in the types of treatment options patients are offered and recommended.
Methods
In order to generate the list of websites, a google search of “vitreous floaters treatment” followed by “[State]” was conducted for every state in the United States, between October and November 2019. The first 20 websites returned from each search were included. Websites were assessed if they represented U.S. based companies or institutions, provided clinical care, addressed vitreous floater treatment on their website, and if the websites allowed for data-mining. Websites unrelated to the topic, including copyright notices, disclaimers, author information, and feedback questionnaires were excluded to ensure that the websites included would mimic the information a patient would seek when searching for information about floaters. Furthermore, websites that were returned from the search that were not specific to the state were also excluded. Two observers (SH and JH) retrieved the data from websites, and any disagreement was resolved with discussion and consensus.
A grading rubric with 22 criteria was then applied to systematically evaluate each website (Table 1). Criteria included whether institutions were public or private, google rank, what treatments were advertised for vitreous floaters, and whether ophthalmologists in the institution completed a surgical retina fellowship, among others. The checklist was developed by the authors (SH, AEK, and JS) in order to comprehensively assess the amount, accessibility, quality, and thoroughness of information presented to the patient. Google rank was correlated with depth of explanation on websites, and the conservativeness of treatment evaluated (1=observation, 2=laser, 3=vitrectomy).
Table 1:
Standardized Checklist Used to Evaluate Websites
| URL |
| Website rank in search engine |
| Name of company/institution |
| Number of locations |
| Academic or private institution? |
| Does website explain what vitreous floaters are? |
| Depth of Explanation (range 1–3) |
| Flesch reading ease score |
| Does website mention that floaters are benign? |
| Does website mention laser as management for floaters? |
| Does website mention vitrectomy as management for floaters? |
| Does website mention observation as management for floaters? |
| What is the main procedure advertised? |
| Does website mention patient results/vision after procedure? |
| Does website mention main advertised procedure complications/risks in general? |
| Does website mention complications from procedures performed on their patients? |
| What are the complications? |
| Does website mention price of procedures? |
| Does website mention insurance coverage? |
| Is there information about physicians in this practice? |
| Is the training of the ophthalmologist/s stated? |
| Did ophthalmologist/s listed complete a surgical retina fellowship? |
Website readability was evaluated using the Flesch Reading Ease score with an online readability tool (http://www.readabilityformulas.com/freetests/six-readability-formulas.php). Readability is a measure of the ease with which a patient can read the website, an important criteria for educational materials to ensure that the material can be understood by the maximum number of patients. Readability was evaluated on a scale of 100, with a higher number correlating to easier reading scores. Reading ease score was also correlated with google rank.
Statistical analyses were performed using the chi-squared test, Pearson’s correlation test, and ANOVA on SPSS 22.0 (SPSS Inc, Chicago, IL) statistical package. A p-value of <0.05 was considered statistically significant.
Results
Of the 1,065 websites screened, 456 met inclusion criteria and were included in the study. Of these, 89% (n=406) were private institutions, 5.3% (n=24) were academic, and 5.7% (n=26) were private with a teaching component at an academic institution. There were 209 websites included from centers with vitreoretinal surgeons, 224 websites included from centers without a trained vitreoretinal surgeon, and 23 websites where the training of their surgeons was not explicitly noted (Table 2). The states of Florida and Texas had the most websites related to treatment for vitreous floaters (n=20), while Wyoming had the least (n=0) (Figure 1). The average Flesch Reading Ease score was 55.5 (95% CI, 54.43–56.57), which correlates to a 10th-12th grade reading level.
Table 2:
Characteristics of Online Websites Discussing Vitreous Floaters
| Private | Academic | Private/ Academic | Total | |
| N | 406 | 24 | 26 | 456 |
| Percentage | 89.0% | 5.3% | 5.7% | |
| Trained VR Surgeon | No VR Trained Surgeon | Training Unspecified | Total | |
| N | 209 | 224 | 23 | 456 |
| Percentage | 45.8% | 49.1% | 5.0% | |
VR: vitreoretinal
Figure 1:
Number of Websites Discussing Vitreous Floater Treatment by State – This figure depicts the number of websites that resulted when “vitreous floaters treatment” followed by “[State]” was searched in Google.
Treatment of vitreous floaters was discussed on 62.1% (n=283) of websites (Table 3). Differences in treatment recommendations between sites run by practices with a vitreoretinal surgeon versus those without a vitreoretinal surgeon are demonstrated in Table 4 and Figure 2. The odds ratio of a center with a retina-trained surgeon to recommend vitrectomy as compared to a center without a retina-trained surgeon was 16.43 (p=0.0003).
Table 3:
Treatment Options Mentioned by Vitreous Floaters Websites Based on Physician Training
| Did physicians complete a surgical retina fellowship? | ||||||
|---|---|---|---|---|---|---|
| No (N=224) | Yes (N=209) | Unspecified (N=23) | Total (N=456) | |||
| Does the website discuss any option for treatment? | No | 69 (30.8%) | 91 (43.5%) | 13 (56.5%) | 173 (37.9%) | p < 0.0001 |
| Yes | 155 (69.2%) | 118 (56.5%) | 10 (43.5%) | 283 (62.1%) | ||
| Does website mention laser as treatment? | No | 145 (64.7%) | 148 (70.8%) | 17 (73.9%) | 310 (68.0%) | p= .328 |
| Yes | 79 (35.3%) | 61 (29.2%) | 6 (26.1%) | 146 (32.0%) | ||
| Does website mention vitrectomy as treatment? | No | 153 (68.3%) | 130 (62.2%) | 17 (73.9%) | 300 (65.8%) | p= .287 |
| Yes | 71 (31.7%) | 79 (37.8%) | 6 (26.1%) | 156 (34.2%) | ||
| Does website mention observation as treatment? | No | 90 (40.2%) | 91 (43.5%) | 17 (73.9%) | 198 (43.4%) | p= .008 |
| Yes | 134 (59.8%) | 118 (56.5%) | 6 (26.1%) | 258 (56.6%) | ||
Table 4:
Vitreous Floater Treatment Recommendation Based on Physician Training Available
| VR Surgeon | No VR Surgeon | Total | |
|---|---|---|---|
| Number of Websites Discussing Treatment | 118 | 155 | 273* |
| Main Treatment Recommendation: | |||
| Observation | 69 (58.4%) | 85 (54.8%) | 154 (56.4%) |
| Laser | 23 (19.5%) | 52 (33.5%) | 75 (27.4%) |
| Vitrectomy | 13 (11.0%) | 1 (0.6%) | 14 (5.1%) |
| No Recommendation | 13 (11.0%) | 17 (11.0%) | 30 (11.0%) |
VR=vitreoretinal
Excludes websites that did not specify training of available physicians
Figure 2:
Recommended Treatment for Vitreous Floaters – This figure compares the differences in vitreous treatment based on the training of physicians.
The majority of websites explained what vitreous floaters are and mentioned that they are generally benign (Table 5). Sixty-three (21.8%) websites that discussed treatment for floaters mentioned side-effects for these treatments. Private institutions were more likely to include an explanation of vitreous floaters than academic institutions (89.4% versus 66.7%, odds ratio: 4.22, p=0.001), as were institutions that did not have a vitreoretinal surgeon compared to practices with a vitreoretinal surgeon (69.2% versus 56.5%, odds ratio: 1.73, p=0.006). With regards to including discussion of potential complications of treatment, there was no significant difference between academic and private institutions (OR=4.3, p=0.123) nor between practices with a vitreoretinal surgeon versus practices without a vitreoretinal surgeon (OR=0.83, p=0.61).
Table 5:
Number of Websites Discussing Prognosis of Vitreous Floaters
| Explanation of Vitreous Floaters | Mention Vitreous Floaters Are Benign | |
|---|---|---|
| Yes | 401 (87.9%) | 291 (62.8%) |
| No | 55 (12.1%) | 165 (36.2%) |
There was an inverse correlation between google rank and depth of explanation in websites (r= −0.114, p=.016). There were no significant correlations between google rank and the conservativeness of treatment (r=−0.123, p=.051) or google rank and Flesch Reading Ease score (r=0.046, p=.750).
Discussion
Patients are increasingly turning to the Internet to aid in making health-related decisions10 and yet the majority of information on the internet is not quality-assessed, leading to potential bias and misinformation. Factors that have been shown to increase the influence the Internet has on patients’ health related activities are younger age and increased education, making this population more vulnerable.10 Fortunately, our findings indicated that websites that had higher ranks in google searches were correlated with more complete explanations on vitreous floaters. This is critical as higher ranked websites receive significantly more visits than lower ranked ones,11 and thus patients are more likely to visit more informative sites.
In this study, observation was the most recommended treatment overall. Floaters very rarely have negative sequelae, and the gold-standard in most cases is observation.5 While observation was the recommendation of most of the websites assessed, most did not include a discussion of the benign prognosis, and nearly a third of websites recommended laser treatment or vitrectomy, with practices without a retinal surgeon more likely to recommend laser. A possible explanation for this difference could be that in order to perform a vitrectomy procedure, an ophthalmologist must generally complete a surgical retina fellowship. Physicians trained in a certain therapeutic procedure for floaters may provide only partial treatment information on their online platform, in order to highlight their area of expertise. As a result, non-retina trained specialists may disproportionately advertise Nd-Yag lasers on their website, whereas retina trained specialists may be more inclined to sway readers towards considering vitrectomy.
Of note, less than a quarter of the websites recommending a treatment option discussed possible complications, with similar rates between academic and private websites as well as practices with and without a vitreoretinal surgeon. Regarding laser vitreolysis, studies have reported improved visual functioning with laser,12 but potentially an increased chance of complications such as delayed retinal tears on long-term follow-up.13 The concern for complications with laser vitreolysis is reinforced by data published by the American Society of Retinal Specialists Research in Safety in Therapeutics (ASRS ReST) Committee describing reported post-laser incidence of glaucoma, lenticular capsular defect, retinal tear, and retinal detachment.14 Similarly, vitrectomy has been demonstrated to be beneficial in reducing impairment from vitreous floaters and is potentially cost effective.15–17 However, vitrectomy in this same series was associated with its own set of complications, including retinal tear, retinal detachment (occurring in 1.5 to 3.1% of cases), and endophthalmitis. This has led many retinal specialists to take a conservative approach toward the management of symptomatic vitreous floaters, with a survey revealing that only 25% of retinal specialists would ever perform vitrectomy for this indication, primarily citing safety concerns.18, 19 All of the complications listed for laser vitreolysis and vitrectomy have the potential to have serious consequences, including loss of vision. Thus, the significant proportion of websites recommending either of these treatment options without an appropriate discussion of risk reflects the lack of transparency and potential danger to patients in currently available online information. Similar studies of the literature available on treatments for ophthalmologic conditions also found many websites to have incomplete medical information.20, 21 In addition, because the current study focuses on a condition treated procedurally on an elective basis, biased online information could theoretically cause greater influence on treatment decisions.
Our study also found the level of literacy of the literature to be higher than the reading level of the average American.22 The American Medical Association (AMA) states that in order for patient reading material to be accessible and comprehensible to the general public, the document should aim to be at a fifth or sixth grade reading level,22 which translates to a Flesch Reading score of 80–100. In the websites included in this study, the average Flesch Reading Ease score was 55, a reading level suitable for 10th-12th graders. Only 1% of the studies that were analyzed had a Flesch Reading score of above 80. This suggests that the information presented online is fairly difficult to interpret by the lay population. Furthermore, the Flesch reading score is primarily dependent upon the number of syllables and the length of sentences.23 As a result, the FRE does not take into account the technical nature of medical terminology, thus potentially overestimating the score. Studies assessing the level of readability of online information in a wide range of specialties including obstetrics and gynecology and urology have concluded that the readability level is significantly more challenging than the recommendation by the AMA.24, 25 The current study supports these results and suggests that the readability of online health information may be a barrier to accessible health information.
Limitations
This study has some inherent limitations. Firstly, this study focused specifically on the treatment for vitreous floaters and may not be applicable to other treatments for ophthalmologic conditions. Secondly, websites were assessed by individuals in the medical field. While every effort was made to objectively assess the websites, it is possible that other individuals’ experience reading and grading the websites would differ. Similarly, it is possible that patients would use different search terms to search for vitreous floater treatment. Incorporating analyses of the patients’ understanding of the websites would further strengthen this study.
Our study included a significantly larger number of sources from private organizations (n=432) than academic institutions (n=24). Academic institutions in general are considered to have less bias and stricter guidelines for publishing online health information.26 When treatments can be directly advertised to patients via the internet, advertising from companies that have a vested interest in the treatments offered raises concerns regarding the accuracy and completeness of the information provided.27 In a study of Internet-based marketing claims for stem cell intervention, Turner et al found that articles by commercial providers raised ethical concerns because they had less peer-reviewed evidence, falsely advertised the safety and efficacy of procedures, and posed risks to vulnerable populations.28 Another study assessing online advertisement of stem cell therapies for ocular conditions concluded that caution must be employed when considering treatments offered by commercial clinics.29 Our results demonstrate that private institutions are four times more likely to include more educational information about floaters on their websites than academic institutions, possibly for practice building purposes. The greater information provided by private institutions and corresponding higher website traffic likely underlies the far greater proportion of private institutions in the top 20 search results as determined by the Google search algorithm.
Another limitation of this study is that 32 websites (7.0%) did not list a treatment as preferred and 173 websites (37.9%) did not mention treatment at all for vitreous floaters. These websites focused on providing educational material over advertising a specific procedure. This could have skewed our results analyzing the websites offering treatment recommendations since the data analysis was conducted on a subset of the overall studies. Lastly, the aesthetic of each website was not taken into account. Factors such as font size, color, and amount of white space may impact how easily information was read, but we did not include these factors because we believed they were more subjective than the measures chosen.
Conclusion
The quality of online information regarding treatment for vitreous floaters is variable, often incomplete, and may not provide patients with adequate information to make well-informed medical decisions. This is critical considering that floaters are a common eye complaint that will be experienced by the majority of the population at some point in their lives and the increasing use of the internet as a source for patient health information. There is a need for more non-biased organizations, which have stricter guidelines such as professional medical societies and academic institutions,30 to develop and regulate online patient materials regarding vitreous floater treatment to ensure that patients have the necessary tools to make well-informed healthcare choices.
Acknowledgments
Funding
Bascom Palmer Eye Institute received funding from the NIH Core Grant P30EY014801, Department of Defense Grant #W81XWH-13-1-0048, and a Research to Prevent Blindness Unrestricted Grant. The sponsors or funding organizations had no role in the design or conduct of this research
Footnotes
Disclosure of Interest
The authors report no conflict of interest
References
- 1.McMullan M Patients using the Internet to obtain health information: how this affects the patient-health professional relationship. Patient Educ Couns 2006; 63: 24–28. 2006/01/13. DOI: 10.1016/j.pec.2005.10.006. [DOI] [PubMed] [Google Scholar]
- 2.Berland GK, Elliott MN, Morales LS, et al. Health information on the Internet: accessibility, quality, and readability in English and Spanish. JAMA 2001; 285: 2612–2621. 2001/05/23. DOI: 10.1001/jama.285.20.2612. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Ahmad F, Hudak PL, Bercovitz K, et al. Are physicians ready for patients with Internet-based health information? J Med Internet Res 2006; 8: e22. 2006/10/13. DOI: 10.2196/jmir.8.3.e22. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Webb BF, Webb JR, Schroeder MC, et al. Prevalence of vitreous floaters in a community sample of smartphone users. Int J Ophthalmol 2013; 6: 402–405. 2013/07/05. DOI: 10.3980/j.issn.2222-3959.2013.03.27. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Milston R, Madigan MC and Sebag J. Vitreous floaters: Etiology, diagnostics, and management. Surv Ophthalmol 2016; 61: 211–227. 2015/12/19. DOI: 10.1016/j.survophthal.2015.11.008. [DOI] [PubMed] [Google Scholar]
- 6.Sebag J, Yee KM, Wa CA, et al. Vitrectomy for floaters: prospective efficacy analyses and retrospective safety profile. Retina 2014; 34: 1062–1068. 2013/12/04. DOI: 10.1097/IAE.0000000000000065. [DOI] [PubMed] [Google Scholar]
- 7.Mura M, Engelbrecht LA, de Smet MD, et al. Surgery for floaters. Ophthalmology 2011; 118: 1894–1894 e1891. 2011/09/06. DOI: 10.1016/j.ophtha.2011.05.020. [DOI] [PubMed] [Google Scholar]
- 8.Tan HS, Mura M, Lesnik Oberstein SY, et al. Safety of vitrectomy for floaters. Am J Ophthalmol 2011; 151: 995–998. 2011/04/05. DOI: 10.1016/j.ajo.2011.01.005. [DOI] [PubMed] [Google Scholar]
- 9.Ivanova T, Jalil A, Antoniou Y, et al. Vitrectomy for primary symptomatic vitreous opacities: an evidence-based review. Eye (Lond) 2016; 30: 645–655. 2016/03/05. DOI: 10.1038/eye.2016.30. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Bujnowska-Fedak MM and Wegierek P. The Impact of Online Health Information on Patient Health Behaviours and Making Decisions Concerning Health. Int J Environ Res Public Health 2020; 17 2020/02/07. DOI: 10.3390/ijerph17030880. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Chaffey D Comparison of Google clickthrough rates by position. Smart Insights 2016. [Google Scholar]
- 12.Shah CP and Heier JS. YAG Laser Vitreolysis vs Sham YAG Vitreolysis for Symptomatic Vitreous Floaters: A Randomized Clinical Trial. JAMA Ophthalmol 2017; 135: 918–923. 2017/07/21. DOI: 10.1001/jamaophthalmol.2017.2388. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Shah CP and Heier JS. Long-Term Follow-Up of Efficacy and Safety of YAG Vitreolysis for Symptomatic Weiss Ring Floaters. Ophthalmic Surg Lasers Imaging Retina 2020; 51: 85–88. 2020/02/23. DOI: 10.3928/23258160-20200129-04. [DOI] [PubMed] [Google Scholar]
- 14.Hahn P, Schneider EW, Tabandeh H, et al. Reported Complications Following Laser Vitreolysis. JAMA Ophthalmol 2017; 135: 973–976. 2017/07/28. DOI: 10.1001/jamaophthalmol.2017.2477. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Sebag J, Yee KMP, Nguyen JH, et al. Long-Term Safety and Efficacy of Limited Vitrectomy for Vision Degrading Vitreopathy Resulting from Vitreous Floaters. Ophthalmol Retina 2018; 2: 881–887. 2019/05/03. DOI: 10.1016/j.oret.2018.03.011. [DOI] [PubMed] [Google Scholar]
- 16.Rostami B, Nguyen-Cuu J, Brown G, et al. Cost-Effectiveness of Limited Vitrectomy for Vision Degrading Myodesopsia. Am J Ophthalmol 2020. 2020/03/07. DOI: 10.1016/j.ajo.2020.01.015. [DOI] [PubMed] [Google Scholar]
- 17.Lin Z, Zhang R, Liang QH, et al. Surgical Outcomes of 27-Gauge Pars PLana Vitrectomy for Symptomatic Vitreous Floaters. J Ophthalmol 2017; 2017: 5496298. 2018/01/11. DOI: 10.1155/2017/5496298. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Henry CR, Smiddy WE and Flynn HW Jr. Pars plana vitrectomy for vitreous floaters: is there such a thing as minimally invasive vitreoretinal surgery? Retina 2014; 34: 1043–1045. 2014/03/05. DOI: 10.1097/IAE.0000000000000124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Cohen MN, Rahimy E, Ho AC, et al. Management of Symptomatic Floaters: Current Attitudes, Beliefs, and Practices Among Vitreoretinal Surgeons. Ophthalmic Surg Lasers Imaging Retina 2015; 46: 859–865. 2015/10/03. DOI: 10.3928/23258160-20150909-11. [DOI] [PubMed] [Google Scholar]
- 20.Ivastinovic D, Wackernagel W and Wedrich A. Accuracy of Freely Available Information About Rhegmatogenous Retinal Detachment on the Internet. JAMA Ophthalmol 2019; 137: 113–114. 2018/10/05. DOI: 10.1001/jamaophthalmol.2018.4682. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Kloosterboer A, Yannuzzi NA, Patel NA, et al. Assessment of the Quality, Content, and Readability of Freely Available Online Information for Patients Regarding Diabetic Retinopathy. JAMA ophthalmology 2019; 137. DOI: 10.1001/jamaophthalmol.2019.3116. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Weiss BD. Health literacy. American Medical Association 2003; 253. [Google Scholar]
- 23.Smart JM and Burling D. Radiology and the internet: a systematic review of patient information resources. Clin Radiol 2001; 56: 867–870. 2001/10/18. DOI: 10.1053/crad.2001.0738. [DOI] [PubMed] [Google Scholar]
- 24.Nwachuku N, Carson T, Fahimuddin F, et al. Readability of Online Patient Educational Materials Provided by Major Gynecological Societies [16OP]. Obstetrics & Gynecology 2017; 129 Suppl 1: 6S–6S. DOI: 10.1097/01.AOG.0000513945.22985.af. [DOI] [Google Scholar]
- 25.Dalziel K, Leveridge MJ, Steele SS, et al. An analysis of the readability of patient information materials for common urological conditions. Can Urol Assoc J 2016; 10: 167–170. 2016/10/08. DOI: 10.5489/cuaj.3578. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Fahy E, Hardikar R, Fox A, et al. Quality of patient health information on the Internet: reviewing a complex and evolving landscape. Australas Med J 2014; 7: 24–28. 2014/02/26. DOI: 10.4066/AMJ.2014.1900. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Connolly R, O’Brien T and Flaherty G. Stem cell tourism--a web-based analysis of clinical services available to international travellers. Travel Med Infect Dis 2014; 12: 695–701. 2014/12/03. DOI: 10.1016/j.tmaid.2014.09.008. [DOI] [PubMed] [Google Scholar]
- 28.Turner L and Knoepfler P. Selling Stem Cells in the USA: Assessing the Direct-to-Consumer Industry. Cell Stem Cell 2016; 19: 154–157. 2016/07/05. DOI: 10.1016/j.stem.2016.06.007. [DOI] [PubMed] [Google Scholar]
- 29.Nirwan RS, Albini TA, Sridhar J, et al. Assessing “Cell Therapy” Clinics Offering Treatments of Ocular Conditions using Direct-to-Consumer Marketing Websites in the United States. Ophthalmology 2019; 126: 1350–1355. 2019/03/25. DOI: 10.1016/j.ophtha.2019.03.019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Aslam N, Bowyer D, Wainwright A, et al. Evaluation of Internet use by paediatric orthopaedic outpatients and the quality of information available. J Pediatr Orthop B 2005; 14: 129–133. 2005/02/11. DOI: 10.1097/01202412-200503000-00014. [DOI] [PubMed] [Google Scholar]