Original Article etiopathogenesis, clinical fi ndings, diagnostic criteria, and treat- ment approaches. Measures VAS was used for pain assessment of patients. VAS was questioned as being VASrest, VASnight, and VASactivity. “I have no pain” was written on one end of a 0–100 mm ruler, and “unbearable pain” was written on the other. The patients were asked to mark the scale according to the level of pain. The score was obtained by measur- ing the distance between the no-pain point and the patient's sign [ 16 ] . The patient satisfaction was evaluated with a Likert scale to eval- uate whether all patients were satisfi ed with the information or the video. The Likert scale is as follows: very satisfi ed, satisfi ed, indeci- sive, dissatisfi ed, and not satisfi ed at all [ 17 ] . B-IPQ consists of 9 items, eight items evaluated with a Likert scale from 0 to 10, and the question asking to indicate the three most important factors that the patient believes to cause the dis- ease. These are; (1) How much does your illness aff ect your life (con- sequences); (2) How long do you think your illness will continue (timeline); (3) How much control do you feel you have over your illness (personal control); (4) How much do you think your treat- ment can help your illness (treatment control); (5) How much do you experience symptoms from your illness (identity); (6) How con- cerned are you about your illness (concern); (7) How well do you think you understand your illness (coherence). (8) How much does your illness aff ect you emotionally (emotional response) [ 18 ] . Statistical Analysis A power analysis program, G*Power version 3.1.9.4 software (Heinrich-Heine Universität Düsseldorf, Düsseldorf, Germany). The values of B-IPQ-concern were taken into consideration for the post- hoc power analysis. The power of the study was 0.97 for α = 0.05, with a sample size of 50 in the control group and 50 in the study group. Statistical analysis was performed using SPSS 23.0 (IBM, Ar- monk, NY, USA) statistical package program. Descriptive statistics were given as a number ( %) for discrete variables, as mean ± stand- ard deviation or median (IQR [ 25 ] –75]) for continuous variables. The compliance of the data with normal distribution was evaluat- ed with the Kolmogorov-Smirnov test and histogram. A Chi-square test was used for discrete variables to compare the diff erences be- tween groups. Student’s t-test was used in the paired comparison between groups conforming to normal distribution; Mann-Whit- ney U test was used for pairwise comparison of data that did not conform to normal distribution. Wilcoxon-signed-rank test was used in paired comparison within non-normally distributed group. Analysis of covariance was used to assess differences between groups in changes in outcome variables over time, controlling for baseline values. The signifi cance level was accepted as p < 0.05. Results The demographic and clinical characteristics of the participants are presented in ▶ Table 1 . The mean age of 50 patients in the video group was 60.06 ± 8.69, while the mean age of 50 patients in the control group was 62.72 ± 8.47. Women constituted the larg- est patient group in the study population. 41 (82.0 %) women in the video group and 39 (78.0 %) women were in the control group. There was no statistically signifi cant diff erence between the two groups in terms of age, gender, body mass index, occupation, mar- ital status, symptom duration, systemic illness, educational status, and social media-internet usage (p = 0.125, p = 0.803, p = 0.133, p = 0.278, p = 0.525, p = 0.204, p = 0.587, p = 0.794, p = 0.812, re- spectively). When both groups were compared in VASrest, VASnight, and VASactivity levels, there was no statistically signifi - cant diff erence (p = 0.617, p = 947, p = 0.169, respectively). Accord- ing to the patient satisfaction, while all of the patients in both groups were satisfi ed with the information provided, the satisfac- tion level of the patients in the video group was signifi cantly high- er than the control group (p < 0.001). There was no statistical diff erence in the initial consequences in the video group compared with post-informing (p = 0.833). In the video group, when the timeline, personal control, treatment control, identity, concern, coherence, emotional response were compared with the baseline, a statistically signifi cant improvement was found after the information (p < 0.001, p < 0.001, p < 0.001, p = 0.009, p < 0.001, p < 0.001, p = 0.001, respectively). In the control group, when the consequences, concern, coherence, were compared with the baseline, there was no statistically signifi cant diff erence after informing (p = 721, p = 0.229, p = 0.128, respectively). When the timeline, personal control, treatment control, identity, emotional response was compared with the baseline in the control group, a statistically signifi cant improvement was found after the informa- tion (p = 0.018, p < 0.001, p < 0.001, p = 0.011, p = 0.001, respec- tively) ( ▶ Table 2 ). The eff ect size of B-IPQ-concern values was 0.784. After the in- itial B-IPQ values were controlled as covariant, when the personal control, concern, coherence values of the B-IPQ in the video group after the information were compared with the control group, a sta- tistically significant difference was found (p < 0.001, p = 0.002, p. < 0.001, respectively). When both groups were compared in terms of consequences, timeline, treatment control, identity, and emotional response, there was no statistically signifi cant diff erence (p = 0.389, p = 0.067, p = 0.079, p = 0.155, p = 0.864, respectively) ( ▶ Table 3 ). Discussion To our knowledge and based on our detailed research in the litera- ture, the present study is the fi rst to evaluate the eff ect of visual and auditory information on illness perception and patient satis- faction by having patients with knee OA watch video with an elec- tronic guide. The most important fi nding of this study was deter- mined as that the patients in the video group had more control over their knee OA (personal control), their anxiety about knee OA de- creased more (concern), and they understood knee OA better (co- herence) after informing when compared to the control group. While all of the patients in the video group and the control group were satisfi ed with the information provided, the satisfaction level of the patients in the video group was higher than that of the pa- tients in the control group. The more information about the disease was given to the patient, the greater confi dence and belief in the treatment. However, while 40 Karabaş Ç et al. The Eff ect of Visual … Phys Med Rehab Kuror 2022 ; 32 : 38 – 44 | © 2021 . Thieme. All rights reserved.