INTRODUCTION
Stroke remains the second leading cause of death and the third major cause of disability globally (GBD 2019 Stroke Collaborators, 2021). In Saudi Arabia, the annual rate of stroke cases is 29 per 100,000 persons (Alqahtani et al., 2020). Approximately 80% of patients with stroke experience motor impairment, and in over 30% of these cases, it is linked to persistent disability and reliance (Langhorne et al., 2009). It is imperative to devise more effective and easily accessible rehabilitation techniques, as well as national stroke rehabilitation policies and strategies, in order to monitor and improve the healthcare services provided to disability-adjusted life years of stroke patients. Several rehabilitation approaches have been utilized for participants after stroke such as intensive exercise programs, functional electrical stimulation, and transcranial direct current stimulation (tDCS).
tDCS has become a viable supplementary treatment to modulate neuroplasticity and motor cortex excitability owing to its safe, convenient, and portable profile (Marquez et al., 2015; Woods et al., 2016). Hence, it has shown potential in improving or disrupting cognitive functions as well as being beneficial in improving a variety of neurological and psychiatric impairments (Antonenko et al., 2019). Among the widely used procedures of tDCS delivery in post-stroke cases, the current at an intensity of 1-2 mA (0.029-0.057 mA/cm2), is commonly employed via saline-soaked anodal and cathodal electrodes (sized between 25 and 35 cm2) secured on scalp using a 10:20 electroencephalogram (EEG) system. A reference electrode is placed over the supraorbital region (Stagg and Nitsche, 2011). Among the widely used procedures, the multiple tDCS sessions in conjunction with neurorehabilitation may be used over a range of ischemic stroke types. Even though research on tDCS and post-stroke motor recovery has surged in the past decade with >1500 research articles being published, large-scale, multicenter trials are still required to formally establish tDCS’s clinical evidence (Cappon et al., 2016; Grefkes and Fink, 2016; Feng et al., 2018).
In several countries, non-invasive brain stimulation methods like tDCS and repeated transcranial magnetic stimulation have been investigated as possible aids to post-stroke rehabilitation; however, there is no previous study measuring the clinical physiotherapists’ knowledge, attitude, and practices (KAPs) of such procedures in Saudi Arabia. Knowledge is the ability to gather, retain, and apply information appropriately; attitudes are the inclinations to respond to a situation; and perceptions are ideas, beliefs, or views about a subject (Goldsworthy and Hordacre, 2017). Geographical location, sociocultural background, therapist qualification, work experience, patient awareness about the device, caregivers’ support, healthcare system structure, and policies are among the several key factors in determining the KAPs of tDCS use. Inadequate training, barriers, and gaps in knowledge may cause misconceptions, low satisfaction, and irrational expectations (Puspitasari et al., 2020). The present study aimed to fill the scarcity of literature as there is no validated instrument that evaluates the clinical physiotherapist’s KAPs related to post-stroke tDCS application in Saudi Arabia. Therefore, the aim of this study was to develop and content validate a questionnaire to assess physiotherapist’s KAPs toward the use of tDCS post-stroke. It will also identify the aspects that, in primary healthcare attention, need to be improved in terms of approach, diagnosis, and tDCS application, with the objective of contributing to the improvement in stroke rehabilitation among patients in Saudi Arabia.
METHODS
Ethical considerations
The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines were followed during the execution of the present research. The Standing Committee for Scientific Research, Jazan University (HAPO-10-Z-001) (reference no.: REC-45/03/754) granted ethical approval for the study. The trial is registered at ClinicalTrials.gov with ID: NCT06110169. The study has been conducted in accordance with the ethical standards for the medical research involving human participants, good clinical practice, and the Declaration of Helsinki (revised 2013). The experts were informed of the aims and objectives of the study and their implied consent was obtained. Participation of experts in the study was completely voluntary; they were not provided with any compensation for it.
Recruitment criteria
The inclusion criteria were experts in the field of neurosciences with ≥5 years of work experience in treating stroke patients preferably with relevant published work in peer-reviewed journals. Experts not meeting these enumerated requirements were excluded from this study. Experts holding highest academic titles and directly involved in treating stroke patients were prioritized. A total of 48 interdisciplinary experts in the field of neurosciences (neurologist, clinical neuroscientist, neuroscience academicians, neurophysiologist, clinical physiotherapist, and physician) were invited to participate, and only 32 (14 females) volunteered (recruitment rate: 67%) between the age group of 29 and 54 years, with a work experience between 5 and 22 years.
Study design and setting
This cross-sectional study was conducted at the Physical Therapy Department of the College of Applied Medical Sciences at Jazan University in Saudi Arabia, between November 2023 and February 2024. The study design was a mixed-methods design. Phase 1 (qualitative phase) involved developing the questionnaire and Phase 2 (quantitative phase) involved validating it (Arora et al., 2017).
Phase 1: questionnaire development
The questionnaire items and domains were designed following a systematic methodical approach comprising extensive literature review and focus group discussions (FGDs) with a panel of four experts (Eignor, 2001) (Table 1).
Questionnaire development and validation.
| Steps | Activity | Methodical approach | Total domains/items at the end of each step | Addition or subtraction of domains/items | Participants [number (N) and area of expertise] |
|---|---|---|---|---|---|
| I | Development framework | Literature search | 3/24 | - | Authors |
| II | Development framework | FGDs | 4/32 | Addition of 1/8 | N = 4 neurosciences experts |
| III | Item generation | Develop items | 4/32 | - | Authors |
| IV | Establishment of content validity | Expert validation | 4/21 | Deletion of 11 items | N = 6 neurosciences experts |
| V | Establishment of face validity | Expert validation | 4/21 | - | N = 10 clinical physiotherapists |
| VI | Pilot testing | Assessment of items | 4/21 | - | N = 12 clinical physiotherapists |
Abbreviation: FGDs, focus group discussions.
Literature review
The first step was a meticulous literature analysis using search engines such as Google Scholar and PubMed, to comprehend the current evidence on the KAPs of clinical physiotherapists addressing post-stroke tDCS application. The keyword string was used in conjunction with the following phrases: (“Stroke” OR “Post-Stroke”) AND (“tDCS” OR “Transcranial Direct Current Stimulation” OR “non-invasive brain stimulation”) AND (Knowledge∗ OR understand∗ OR literacy∗) AND (“Attitude OR belief OR perception”) AND (“Practice OR Behaviour”). This initial search found 150 related articles. After screening the titles, abstracts, and entire texts, five publications were deemed relevant, leading to the generation of 24 items in three domains (Table 1) (Ecker and Skelly, 2010).
Focus group discussions
The FGDs were executed with four interdisciplinary experts in neuroscience areas of expertise. In-depth interviews were carried out to aid the formulation of appropriate items and domains for incorporation in the questionnaire. The questions were framed in simple unambiguous language. Items were organized in an appropriate sequence to prevent overlapping (Mccallister, 1998). The initially generated questionnaire had 32 questions distributed in four domains: 1: “Sociodemographic profile”; 2: “Theoretical knowledge”; 3: “Attitudes”; and 4: “Practices and barriers.”
Phase 2: questionnaire validation
Content validity
Initially, a minimum number of five experts was stipulated for content validity. To eliminate risk of dropouts, 12 experts were invited via convenient sampling and were requested to respond within 10 days (Yusoff, 2019). The Delphi technique was used to evaluate the developed questionnaire for critical appraisal and content was validated by a team of six experts from the departments of Neurology, General Medicine, Neurophysiotherapy, and Physiology from different regions of Saudi Arabia. The Delphi process followed a sequence in the form of questionnaire development, selection of panel experts according to predefined criteria, iterative Delphi rounds, and predefined closing criteria, i.e. achievement of consensus among experts. A series of rounds of controlled feedback questionnaires allows experts to express their opinions on each domain and item to determine the most reliable consensus on each topic (Grant and Kinney, 1992). A Likert scale measure was developed to aid experts in assessing the questionnaire items and domains in terms of necessity, relevancy, and clarity (Table 2). The following close-ended questions and an open-ended question were framed to assess necessity, relevancy, and clarity of each item and domain (Wynd et al., 2003; Zamanzadeh et al., 2015):
The Likert scale measures sent to experts to assess questionnaire items and domains for content validity.
| Marking | Necessity (need of each question) | Relevancy (to determine the importance of domain/item for the tool) | Clarity (language clarity) |
|---|---|---|---|
| 1= | Not necessary | Not relevant | Not clear |
| 2= | Useful but not essential | Somewhat relevant (the item requires some revision) | Somewhat clear (the item requires some revision) |
| 3= | Essential | Quite relevant (the item requires minor revision) | Quite clear (the item requires minor revision) |
| 4= | - | Very relevant | Very clear |
Is this domain/item necessary? Is this question pertinent for the research topic?
Are the domains and items comprehensive? Do they address all the essential elements of the topic?
Is the question relevant?
Is it important to know the content addressed in the question?
Are questions and answers clear? Is all content free from potential for misunderstanding? Is the answer consistent with the question?
Open-ended question: Is there anything in this questionnaire that could be added to or modified? Which one? (Table 2).
Face validity
Using the maximum diversity principle, on the basis of sociodemographic parameters such as age, gender, and socioeconomic and education status, 10 clinical physiotherapists who could speak and understand English and are routinely treating stroke patients were enrolled. After the open-ended conversation, the respondents were requested to evaluate each domain and item on the questionnaire about how it was presented (layout and setting) and lack of ambiguity. Their varied reactions and comprehension of the domains/items were assessed with the following questions: does the statement make sense? And is it clear from the first reading? To confirm that the respondents comprehended the revised wording, the modified items were once more pre-tested on the same respondents (Cicchetti and Sparrow, 1981; Nunnally and Bernstein, 1994).
Pilot testing
After content and face validity, the questionnaire was further pilot-tested among 12 clinical physiotherapists treating stroke patients for ≥3 years in various regions of Saudi Arabia to identify practical challenges, assess respondents’ accurate comprehension of the topic, and lessen respondent burden. Other considerations include time constraints, grading criteria, and final interpretations (Julious, 2005).
Statistical analysis
SPSS version 20.0 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis at the 0.05 level of significance. Continuous and categorical variables were described with means and frequency, respectively. Microsoft Excel was used for the expert panel evaluation to analyze the content validity. The content validity ratio (CVR) determines the quantitative content validity by scoring expert opinion on the necessity of each domain and item (Table 2). The CVR formula is (Ne − N/2)/(N/2), where Ne is the total number of experts saying the item is “essential,” and N is the total number of experts; values vary between 1 and −1. The acceptable numeric value for the necessity of an item in an instrument evaluated by a six-expert panel is 0.99 according to Lawshe’s table (Lawshe, 1975).
The content validity index (CVI) measures the relevancy and clarity of each domain and item. The item-level CVI (I-CVI) score was calculated by number of experts evaluating each item as 3 (quite relevant) or 4 (highly relevant) (Table 2), divided by the total number of experts (CVI ≥ 0.80 represented excellent level). Scale-level CVI (S-CVI) was calculated based on the universal agreement method [(S-CVI/UA) = (sum of items considered relevant by all experts/total number of the items)] (Mccallister, 1998). Kappa value (κ) was calculated as (I-CVI − Pc)/(1 − Pc), where Pc is the probability of a chance occurrence calculated as PC = [N!/A! (N − A)!]* · 5N, where N is the total number of experts and A is the number of experts evaluating the item as relevant (3 or 4; Table 2) (κ = 0.75 indicates an excellent value) (Cicchetti and Sparrow, 1981).
RESULTS
The final construct after the extensive literature review and FGDs had 32 items across four domains (Table 1). The original draft of the questionnaire was developed in English. The questionnaire was constructed with four domains consisting of 32 questions elaborated as follows: (i) sociodemographic profile including gender, age, ethnicity, qualification, and work experience (5 items); (ii) knowledge section based on tDCS registration, setting parameters, indications, side effects, and complication aspects (10 items); (iii) attitude section based on the theory of Health Belief Model (8 items) (Jones et al., 2015); and (iv) practices based on previous research evidence for post-stroke tDCS application (9 items). The responses were documented as “yes,” “no,” and “do not know/somewhat.” To ensure consistency of answers, both negative and positive remarks were included in the questions. One mark was allocated to correct answers and 0 mark was allocated to incorrect responses (Andrade et al., 2020).
For content validation, the conclusions from the respondents’ level of expertise were used to generate appropriate domains and items for the questionnaire. Based on this, 11 items were removed for being redundant or irrelevant (CVR value < 0.99; or CVI < 0.70) and 5 were re-worded to improve the clarity (CVI between 0.70 and 0.79). Two Delphi rounds were conducted in which both CVR (CVR = 1) and I-CVI (I-CVI > 0.80) reached above the acceptable values (Davis, 1992) (Table 3). The S-CVI/UA was 0.86 and is universally accepted (acceptable limit ≥0.80). The κ value varied between 0.75 and 1 (Table 3). Face validity had 100% agreement among 10 participants. The face validity and pilot testing did not result in any elimination of domains or items. Some terminologies were further clarified during the process, such as “long-term effect in terms of improvement of motor or cognitive function among stroke survivors” and “adverse effects, such as brain damage, headache, or burning sensation of the scalp.” The scoring criteria were developed with the opinion of experts who did content validation of items and literature research of previous tools, as well as the practicality discovered in the pilot study. The summation of the scores for every domain yielded the summary score (Table 4).
Content validation of final questionnaire.
| Dimensions of the constructed questionnaire | Number of experts giving a rating of 3 or 4 for relevancy | I-CVI for relevancy | Number of experts giving a rating of 3 or 4 for clarity | I-CVI for clarity | κ value for relevancy | Interpretation |
|---|---|---|---|---|---|---|
| Domain 1: Socioeconomic/demographic details | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 1: Gender | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 2: Age (years) | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 3: Ethnicity | 5 | 0.83 | 5 | 0.83 | 0.79 | Excellent |
| Item 4: Qualification (highest degree) | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 5: Work experience (years) | 6 | 1 | 6 | 1 | 1 | Excellent |
| Domain 2: Knowledge | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 6: What is the status of tDCS treatment in Food and Drug Administration at the United States? (i) Investigational, (ii) Approved, (iii) Do not know | 5 | 0.83 | 6 | 1 | 0.79 | Excellent |
| Item 7: Is Saudi Food and Drug Authority approval required for tDCS treatment? (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 8: Does clinical physiotherapist require to be certified to administer tDCS treatment? (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 9: Is tDCS useful in treating cognitive dysfunctions among stroke survivors? (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 10: Is tDCS useful in treating motor dysfunctions among stroke survivors? (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 11: Does tDCS provide long-term effect in terms of improvement of motor or cognitive function among stroke survivors? (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 12: Should clinical physiotherapists involve in administering tDCS in patients? (i) Yes, (ii) No, (iii) Do not know | 5 | 0.83 | 5 | 0.83 | 0.79 | Excellent |
| Item 13: Are neurologists/neurosurgeons involved in administering tDCS in patients? (i) Yes, (ii) No, (iii) Do not know | 5 | 0.83 | 5 | 0.83 | 0.79 | Excellent |
| Domain 3: Attitudes to tDCS application in stroke rehabilitation | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 14: The procedure of tDCS application among post-stroke patients is associated with adverse effects, such as brain damage, headache, or burning sensation of the scalp. (i) Agree, (ii) Disagree, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 15: The procedure of tDCS application among post-stroke patients should not be used. (i) Agree, (ii) Disagree, (iii) Do not know | 5 | 0.83 | 6 | 1 | 0.79 | Excellent |
| Item 16: I would advise a close relative to receive tDCS if it is recommended. (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 17: I would agree to apply tDCS to my patients if it is recommended. (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Domain 4: Practices and barriers to tDCS application in stroke rehabilitation | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 18: Is tDCS available in your premises to be used as an adjunct therapy among stroke patients? (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 19: Do you feel you are trained in administering tDCS appropriately? (i) Yes, (ii) No, (iii) Somewhat | 5 | 0.83 | 5 | 0.83 | 0.79 | Excellent |
| Item 20: Do you feel you are well aware of indications, contraindications, and parameter settings of tDCS for stroke patients? (i) Yes, (ii) No, (iii) Somewhat | 6 | 1 | 6 | 1 | 1 | Excellent |
| Item 21: Do you feel formal training of tDCS use for stroke patients should be provided to concerned medical personnel? (i) Yes, (ii) No, (iii) Do not know | 6 | 1 | 6 | 1 | 1 | Excellent |
Abbreviations: I-CVI, item-level content validation index; κ value, kappa value; tDCS, transcranial direct current stimulation.
Scoring and interpretation of final validated questionnaire.
| Components of questionnaire | Scoring | Interpretation | |
|---|---|---|---|
| 1. | Knowledge-based questions = 8 (Q6-Q13) | Total maximum score = 8 Total minimum score = 0 (both 0 and −1 coding will be counted as 0) | Knowledge will be categorized as good (score ≥7), average (score 5-6), or poor (score <5) according to the highest score achieved by 30% of respondents during pilot testing (e.g. out of a total of 12 respondents, 30% respondents achieved score ≥7, 40% had score 5-6, and the rest 30% had their score <5). |
| 2. | Attitude/bias-based questions = 4 (Q14-Q17) | Total maximum score = 4 Total minimum score = 0 (both 0 and −1 coding will be counted as 0) | Attitude will be determined as good (score ≥3) and bad (score ≤2) according to the highest score (≥3) achieved by 50% of the respondents in pilot testing. |
| 3. | Practices = 4 (Q18-Q21) | Total maximum score = 4 Total minimum score = 0 (both 0 and −1 coding will be counted as 0) | Practices will be determined as in good practical use (score ≥3) and poor practical use (score ≤2) according to the highest score (score ≥3) achieved by 50% of the respondents. |
Q6-Q21 corresponds to item number on final validated questionnaire.
DISCUSSION
Although tDCS research is still in its early stages, preliminary findings are encouraging. The Kingdom of Saudi Arabia has an excellent opportunity to spearhead the advancement and enhancement of this technology through regional and global collaborations, by carrying out meticulously designed surveys, clinical trials, and experimental investigations. The interlinked KAPs influence clinical physiotherapist’s willingness to choose tDCS therapy as an aid to stroke rehabilitation. Investigation of medical professionals’ knowledge regarding optimum stimulation sites, and parameters and their attitudes, practices, limitations, and perceived barriers in tDCS use among various diseases, can spur improvements in tDCS application among various emotional, psychological, or neuropsychiatric disorders and disabilities (Al-Thaqib et al., 2019).
KAPs regarding post-stroke tDCS application among clinical physiotherapists working in hospitals and various tertiary units in Saudi Arabia who play a significant role in patient care and the decision-making process have rarely been evaluated. The study was conducted to fill the gap in the literature for a better understanding of this topic.
The Delphi technique is a useful process that can incorporate geographically distant experts to provide collective judgment in an easy, rapid, and inexpensive way and is more beneficial than individual opinions (Nasa et al., 2021). The procedure of validation is time-consuming. Three sources were consulted in order to determine items and domains of questionnaire: first an in-depth review of the literature, then FGDs with the experts, and finally an expert discussion in two Delphi rounds (Table 2). We set up and examined content and face validity and both yielded favorable responses, proving the validity of the questionnaire. Taking into account the experts’ opinions (panel size, N = 6), a total of 11 items with CVR less than the critical value, i.e. 0.99 (I-CVI < 0.70), were deleted from the drafted questionnaire. A total of five questions in the first round were revised (I-CVI values “between” 0.70 and 0.8) (Tables 1 and 4). A total of 21 items in four domains were retained and all of the calculated results were within acceptable limits (Table 3). According to the literature, answers on KAP-based questionnaires that have two to three points (“yes,” “no,” and “do not know”) are adequate (Andrade et al., 2020). The scoring and interpretations were determined based on validity phase and pilot testing (Table 4).
Studies on content validity have certain limitations as experts’ feedback may be biased due to its subjectivity and some content may be omitted from instrument if initially content domains are poorly defined. Nonetheless, experts are requested to recommend additional components for the device, which could lessen this limitation (Zamanzadeh et al., 2015). In the present survey, only post-stroke tDCS application was considered, although this was because there are higher cognitive and motor impairments post-stroke and tDCS has shown extensive improvement in cognitive enhancement and motor rehabilitation in stroke (Zhang et al., 2024). At the time of data collection, the type and phase of stroke were not documented. However, in a majority of cases motor and cognitive impairment is seen in all common types of strokes at each stage (Einstad et al., 2021).
Implications and future directions
The recent survey involving participants from diverse areas of expertise in the neuroscience field created a unique questionnaire for documenting the clinical physiotherapists’ KAPs with regard to post-stroke tDCS application. The initial survey will further support training human resources, social marketing, medical ethical rules, financial investments, and therapeutic use of tDCS (Al-Thaqib et al., 2019). To ascertain existing KAPs among medical professionals, potentials, challenges, and regulations of tDCS application will be beneficial to policymakers, governing bodies, grant agencies, researchers, clinicians, and even general public audiences (Fregni et al., 2015). In further recommendations, ordinal scale values could be transformed into an interval scale to calculate the percentage of points for each domain. Questionnaire can be translated into Arabic language to enhance comprehensibility and understanding. It would be valuable to consider internal consistency as well as external validation methods in future research. Comparing the questionnaire results with objective measures or other validated tools would further strengthen the new instrument’s validity.
CONCLUSION
A systematic, subjective, and two-stage process of content validity was conducted with designing and judgment/quantification of questionnaire domains and items by 10 experts in related domains. Face validity and pilot testing of questionnaire were done additionally to double-check for the appearance and comprehensibility of the questionnaire by 22 clinical physiotherapists. It further determined its future utilization in Saudi Arabia to document KAPs among clinical physiotherapists regarding the therapeutic application of tDCS in stroke rehabilitation. The overall CVI of the instrument using universal agreement approach (S-CVI/UA = 0.86) was high and in acceptable ranges.