جستجوی مقالات مرتبط با کلیدواژه "کارآزمایی بالینی" در نشریات گروه "پزشکی"

Rhinoplasty is a challenging and complex surgery because it is designed to meet the unique needs of the patient. In rhinoplasty surgery, many factors contribute to achieving the desired result. These factors include the surgeon's care and observation, analysis of the existing anatomy, choice of surgical technique, degree of soft tissue and cartilage trauma, amount of bleeding, quality of surgical instruments and anesthesia, and anything that helps reduce bleeding.

This double-blind study was conducted on 50 patients aged 18 to 45 years undergoing septorhinoplasty surgery referred to Motahari Hospital in Jahrom city in 2022. Patients were randomly divided into dexmedetomidine and control groups. The degree of sedation, bleeding and surgeon satisfaction were evaluated and recorded. Data analysis was performed using SPSS software, version 21 (IBM SPSS, Armonk, NY, USA) and descriptive statistics (mean, standard deviation, percentage, number, frequency) and inferential statistical tests (Mann-Whitney U test, Kruskal-Wallis, t-test, chi-square test). The significance level in all tests was considered P<0.05.

The majority of patients in the study groups were female and the mean age of patients in the dexmedetomidine group was 34.36±7.33 years and in the control group was 36.60±9.59 years. The study groups were similar in terms of age and body mass index (P<0.05). The frequency of patient sedation in the dexmedetomidine group was lower than the control group, but it was not statistically significant (P<0.05). The results showed that at the beginning of the operation and 90 minutes later, the satisfaction level of the patient surgeon in the dexmedetomidine group was significantly better than the control group (P<0.001). In the dexmedetomidine group, the field of view of the surgeon was relatively clear and completely clear. The amount of bleeding in the dexmedetomidine group was lower than the control group, but it was not statistically significant (P<0.05).

Dexmedetomidine increased the surgeon's satisfaction by reducing bleeding and improving the surgeon's visual field. Therefore, this drug can be used as an anesthetic aid in surgery.

Tendon allografts are valuable tools for reconstructing tendon tissues in several anatomical sites, when autograft or tendon transfer is not available or feasible. For the aim of introducing an ideal tendon graft, in the following investigation, a specific allograft tendon was processed and characterized.

Tendon allograft obtained from hallucis longus and digitorum longus tendon named Double Tendon (DT) was evaluated regarding its structural stability as well as in-vitro biological compatibility. On this basis, a clinical trial including 20 male patients aged between 30-40 years was performed via designing a questionnaire and asking the surgeons to evaluate the predefined qualifications (such as stabilization, repairability, handling, sizing, etc.) of DT during and post-surgery in a 1-year follow-up on a 4-stage ranking (excellent, very good, good, and fail).

According to performed evaluations, this product was capable of tensile load bearing to the ultimate extent of 7.33 ± 0.87 MPa, which is acceptable for a tendon substitute concerning the literature. Regarding the cytocompatibility results, the cellular viability on DT with 98.13 ± 0.18 % was not significantly lower than the cell viability of the control sample. Also, based on the statistical analysis, the surgeons reported satisfaction with DT’s structural attributes and clinical effectiveness since no “fail” was observed in any parameters. Additionally, there were no instances of inflammation, infection, or rejection reported following DT transplantation.

Herein, the DT was introduced as safe and efficient substitute for the aim of tendon tissue repair.

Currently, birth experience is considered an indicator for evaluating the quality of care provided during labor and birth. This study examined the effect of the Iranian positive birth experience guideline on the birth experience of primiparous women.

This randomized controlled clinical trial was conducted at Taleghani Hospital, Tabriz, Iran (2019). Thirty pregnant women admitted to labor after checking the eligibility criteria were randomly assigned to intervention (developed guidelines) and control (routine hospital care) groups. Women’s birth experience was evaluated 24 hours postpartum using the Childbirth Experience Questionnaire (CEQ 2.0). An independent sample t-test was employed to compare the average scores between the groups.

The mean (standard deviation) of the total score of birth experience in the intervention and control groups was 3.0 (0.4) and 2.1 (0.5), respectively. The average score of the childbirth experience in the intervention group was significantly greater than that of the control group [Mean difference: 0.9; 95% confidence interval: 0.5–1.2; P < 0.001].

The Iranian guideline for improving birth experiences was able to improve primiparous women’s birth experiences more effectively than routine care. Practical Implications. The findings of this study can be considered in the policies and management of healthcare centers.

Today, three to eleven percent of the world's population is suffering from psoriasis. This disease causes many physical, psychological, and social complications for patients. Despite the high cost and time of treating this chronic disease, modern medicine has not yet been able to provide a definitive solution for its treatment, however, in most of the old Greek, Iranian, and Indian medical books, complementary medicine and especially leech therapy are introduced as one of the ways to treat this disease. The present study was designed and implemented to determine the effectiveness of leech therapy on the severity and extent of psoriasis.

This randomized, blinded, controlled clinical trial was conducted on 60 patients. Patients were randomly assigned to two intervention groups (routine psoriasis care with leech therapy) and control (receiving routine psoriasis care). The data collection tool included a demographic information questionnaire and the Psoriasis Extent and Severity Index (PASI). Data were analyzed with the help of the spss22 program under Windows and using Kolmogorov Smirnov, independent t, chisquare, and paired t-test.

The majority of the patients were men and held a diploma or higher degree. Before the intervention, the background variables and average PASI scores in the two groups did not have statistically significant differences (P=0.83, t=0.26). After the intervention, the mean score of PASI in the two intervention groups was statistically significantly different from the control group (P=0.004, t=2.94). In the two measurement periods (before and after the intervention), the mean scores of the PASI index in intervention group and in control group had a statistically significant difference.

The implementation of leech therapy is effective in improving the symptoms of psoriasis patients and results in a significant decrease in the PASI score of patients undergoing leech therapy, therefore, leech therapy as a cost-effective method in terms of cost and time can be used alongside Common medical treatments help in the recovery of such patients.

Parents play an important role in the sexual health of adolescents. There are multiple ways to educate adolescents about sexual issues, but the most effective method of imparting sexual knowledge to them is through sexual conversations between parents and adolescents. The aim of improving the sexual health of adolescents has been achieved through the design and implementation of many studies in the field of sexual education of parents, Sexual education for adolescents has been examined through different aspects by each of these. The present study aimed to review the articles that have been conducted in the field of sexual education of parents and the effect of parental educational intervention on the parents' communication skills and adolescent's sexual health.

This study is a systematic review in that relevant articles between 2000 and 2023 were extracted by searching internal and external databases including Magiran, Irandoc, SID, Science Direct, Scopus,  Web of Sciences, PubMed, and DOAJ. Relevant studies were searched using sex education, sexual behavior, parents, adolescents, dialogue, intervention, and clinical trials in external databases and their Persian equivalents in internal databases. Inclusion criteria included types of clinical or semi-experimental trials, the target group of parents, and articles with full text, in Farsi or English. Related articles were reviewed using PICO criteria. So studies conducted on parents (mother, father, or both) and teenagers were considered. In terms of intervention, studies that included educational interventions including lectures, film watching, role-playing, and other educational methods were included in the study. Desirable outcomes for the present study include parents' sexual literacy, parents' skills in communicating with their adolescents, condom use skills, avoiding premature sexual relations, and promotion of adolescents' sexual health.

The number of primary studies found in the relevant databases equaled 66 articles. After removing duplicates (12 articles), articles were screened based on the title and abstract, and as a result, 21 articles were removed due to lack of relevance to the study title. Out of the remaining 33 articles, 13 articles that had full text and matched the inclusion criteria of the present study were included in the study. Based on the results of the included studies in this systematic review regarding the types of effects of parental educational intervention, the results obtained in two categories: the effect of parental educational interventions on parents' communication skills on sexual issues (8 studies) and the effect of parental educational interventions on adolescent’s sexual health (6 studies) were categorized. The findings of the study showed that teaching parents about sexual dialogue can, on the one hand, strengthen the parent's communicational skills regarding parent-adolescent sexual dialogue and increase the self-reliance of parents to solve the sexual problems of adolescents. on the other hand, promoting the sexual health of adolescents, causes them to postpone sex, use condoms, and prevent sexually transmitted diseases and unwanted pregnancy.

From the findings of the study, it can be concluded that educating parents and increasing their awareness of adolescent sexual issues, in addition to improving parents' communicational skills in dealing with adolescent sexual crises, can improve parents' sexual dialogue with adolescents and their avoidance of unhealthy sexual relations, and improve the adolescent’s sexual health.

Nowadays, diabetes mellitus is considered one of the most common diseases affecting the quality of life in the elderly. Therefore, this study was conducted to investigate the effect of self-care training program on health-related quality of life among elderly women with type 2 diabetes mellitus (T2DM).

In this clinical trial, 99 elderly women with T2DM were selected using random cluster sampling and randomly divided into test and control groups in Tehran from 2022 to 2023. The test group received seven sessions of 30-60 minutes of self-care training specific for patients suffering from T2DM, while the control group received the same training in four intensive sessions after the post-test. Data collection tools included a two-part questionnaire on demographic information and quality of life (LEIPAD). Data analysis was performed using SPSS software version 26 software and descriptive and analytical statistical tests.

In this study, 69.7% (69) of the participants were in the age group of 60-69 years. After the intervention, a significant difference was observed in the quality of life scores between the two groups (p<0.001). Within-group analysis also showed a significant difference in the quality of life scores before and after the intervention, with a positive change in the test group and a negative change in the control group (p=0.001).

Self-care education can improve the quality of life of elderly women with T2DM. Therefore, implementing such educational interventions is a suitable option for enhancing the quality of life of elderly women with T2DM.

Mental disorders contribute to a significant global disease burden worldwide. The present study aims to develop and evaluate a transdiagnostic intervention based on the common elements treatment approach (CETA) for mental disorders in Iranian adults.

This mixed-method study (qualitative/quantitative) was conducted in Semnan province, Iran. In the qualitative stage, interviews were conducted using the free listing technique with 20 community members and 10 key informants to extract the common mental disorders. Then, a tool for screening these disorders was designed, and its face validity, content validity, and criterion validity were determined. Next, the CETA-based transdiagnostic program for the treatment of these mental disorders was developed, and three training workshops on implementing the intervention program were held for 30 healthcare providers. Finally, a randomized clinical trial was conducted on 500 adults with mental disorders referred to health centers in Semnan province in two groups of intervention (receiving the CETA-based program) and control (routine treatment), and the effectiveness of the intervention was evaluated.

Three mental disorders, including depression, anxiety, and obsessive-compulsive disorder (OCD), were identified in the qualitative phase. The designed screening tool for measuring these disorders was a valid and reliable tool with 76 items. In this tool, the cut-off points for depression, anxiety, and OCD were 14, 17, and 6, respectively. In evaluating the effectiveness of transdiagnostic intervention, the results showed that the mean scores of depression (P<0.001), anxiety (P<0.001), and OCD (P<0.05) significantly decreased after intervention in both control and intervention groups, where the CETA-based intervention was more effective than the routine treatment. 

The CETA-based transdiagnostic intervention, delivered by healthcare providers to adults with depression, anxiety, and OCD, is a feasible and effective method and can be used to increase the mental health of adults in Iran.

One of the main complications of diabetes is psychological problems, such as reduced stamina and psychological well-being. The use of muscle relaxation is a simple, safe, and non-pharmacological method. Therefore, the present study was designed to investigate the effect of Jacobson's muscle relaxation technique on psychological well-being and resilience in patients with type 2 diabetes.

The current study is a two-group randomized clinical trial with a pre-test and post-test design conducted on 40 patients with type 2 diabetes at the Khayyam Diabetes Clinic in 2021. Eligibility criteria included minimum literacy, acceptable hearing, and speaking ability, age between 25 and 65 years, no history of relaxation training, type 2 diabetes for at least 6 months, no smoking and no alcohol, ability to use a computer, poor psychological well-being and resilience (psychological well-being score equal to or less than 63, resilience score equal to or less than 50), and no definite psychiatric disorders. Exclusion criteria included: special medical conditions (such as hospitalization or medical inability to continue treatment), withdrawal from the research, death, unwillingness to cooperate, incomplete completion of questionnaires by members, and failure to perform sedation for more than 4 sessions. The samples were selected using the available methods and then randomly allocated with permutation blocks to two intervention and two control groups. The relaxation technique was then practiced at home by the intervention group once a day for 8 weeks. Rif's psychological well-being questionnaire and Connor's resilience questionnaire were completed by the intervention and control groups at the beginning and end of the intervention. Data were analyzed using the Shapiro-Wilk test for normality, Fisher's exact test, chi-square, and analysis of covariance using SPSS 25 software.

The results of the research showed that the two groups were homogeneous in terms of gender, marriage, age, education, history of chronic diseases, history of neuro medications, insulin history, exercise history, peer history, dietary compliance, income, and occupation and there was a statistically significant difference. There was no difference in these variables between the two groups (P>0.05). The results of the covariance test show that the means of the experimental and control groups are the same in terms of patient resilience (P=0.49, eta=0.02). Therefore, it can be concluded that there is no significant difference between the experimental and control groups in terms of patient endurance, controlling for the effect of pre-test means. Also, the means of the experimental and control groups differ in psychological well-being (P=0.00, eta=0.44). Therefore, It can be concluded that there were statistically significant differences between the groups. More specifically, there was a significant difference between the experimental and control groups in terms of psychological well-being, controlling for the effect of pre-test means.

 Results of the study showed that muscle relaxation training was an effective, practical, and inexpensive method of improving and preventing psychological problems in people with diabetes in the intervention group compared with the control group.

Laparoscopic cholecystectomy has been accepted as a safe and gold-standard procedure in the world and has many advantages. However, one of the common complications after laparoscopic cholecystectomy is chronic and sometimes very severe pain. Considering the patients' need to control postoperative pain with drugs that have the least possible side effects, as well as limited studies on the effect of painkillers on pain caused by laparoscopic cholecystectomy, the purpose of this study is to compare the preemptive effect of two drugs. Apotel and ketorolac were used for the first time in patients undergoing laparoscopic cholecystectomy.

This study was conducted as a three-blind randomized clinical trial on 90 patients aged 18 to 68 years, with ASA class one and two, who underwent general anesthesia for cholecystectomy.

The findings of this study show generally, the need for narcotics after cholecystectomy surgery in patients under anesthesia with ketorolac was less than in Apotel and the control group. These findings were also confirmed in patients' pain intensity and patients' satisfaction, so patients' satisfaction in Ketorolac and then Apotel group was higher compared to the control group, which is in line with previous studies in this field.

Therefore, it seems that the overall need for narcotics was lower in the ketorolac group than in Apotel and lower in Apotel than in control.

A significant portion of the population suffers from maladaptive perfectionism, which, without appropriate psychological treatment, can lead to various psychological disorders and impairments in occupational, social, and educational functioning. Therefore, the present study aimed to examine the effectiveness of cognitive-behavioral therapy in reducing perfectionism.

This study utilized a quasi-experimental design with a pretest-posttest and follow-up period, including a control group. The target population consisted of all students of Zanjan University of Medical Sciences in 2020. The sample was selected in two stages: first, 350 individuals were selected from the target population using convenience sampling, and the Frost Multidimensional Perfectionism Scale (FMPS) was administered to them. In the second stage, individuals who scored above the diagnostic cutoff point (score equal to or higher than 90) on the FMPS were selected (n = 314). Finally, based on entry and exit criteria and the progression of subsequent stages, a sample of 40 individuals was randomly assigned to the experimental group (n = 20) and the control group (n = 20). The inclusion criteria included residence in Zanjan at the time of the study, willingness to participate in the research, and scoring above the diagnostic cutoff on the FMPS. The exclusion criteria included the onset of psychiatric illnesses during the intervention, previous experience of cognitive-behavioral interventions, particularly more than 5 sessions of cognitive-behavioral therapy, more than two consecutive absences in the group protocol, failure to participate in one of the three assessment stages, and obtaining a score of 140 or higher on the FMPS. The experimental group received group cognitive-behavioral therapy based on perfectionism once a week for 90 minutes. The participants were assessed at three-time points: pretest, posttest, and two-month follow-up. The data were analyzed using SPSS-25 software and repeated measures analysis of variance.

The results of the analysis indicated that group cognitive-behavioral therapy led to a significant improvement in overall perfectionism scores, particularly in the subscales of concerns over mistakes and parental criticism (p < 0.05). The mean pretest score for overall perfectionism in the experimental group was 83.110, which decreased to 39.98 in the posttest. For the subscale of concerns over mistakes, the mean scores at the pretest and posttest were 72.10 and 22.9, respectively. Finally, for parental criticism, the mean scores at pretest and posttest were 28.8 and 61.7, respectively. These improvements were significant compared to the control group.

The findings of this study support the effectiveness of group cognitive-behavioral therapy as an intervention that can reduce maladaptive perfectionism in individuals with perfectionistic traits. Therefore, therapists can utilize this treatment to improve perfectionism in their clients.

Pregnant women usually prefer medicinal plants over chemical drugs due to physical and mental problems. The use of chamomile plants to control problems during pregnancy and childbirth has been studied in many studies, and the present study has investigated the results of these studies as a review study.

This study, which was conducted as a narrative review, examined all the articles that were the result of clinical trials in Farsi and English from 2010 to 2024.

Finally, 14 articles were examined in this study. There were studies related to the role of chamomile on pregnancy nausea and vomiting, pain and anxiety during childbirth, sleep quality of pregnant women, labor contractions, postpartum bleeding, pain and episiotomy wound healing.

To some extent, the reviewed studies support chamomile's positive role in improving some disorders during pregnancy and childbirth. No special complications of this plant were observed in the studies. Thus, considering the cheapness and availability of this plant and our society's interest in using traditional Iranian herbal medicines, herbal medicines may be used as a complementary treatment along with common medications. More extensive studies in this field are required.

Despite the effect of vitamin D in improving clinical and laboratory symptoms and insulin resistance and hyperandrogenism, there are still doubts about the role of vitamin D in the treatment of PCOS. Therefore, the present study was conducted with aim to investigate the effect of vitamin D on biochemical indices and sexual hormones in PCOS patients.

This clinical trial study was conducted in 2023 on 213 women aged 18-40 with PCOS diagnosis and vitamin D deficiency in Shahid Akbarabadi Hospital. Patients with a serum level greater than or equal to 30 ng/ml of vitamin D were included in the study and were divided into control and intervention groups. The control group was prescribed metformin 500 mg daily and the intervention group metformin 500 mg daily plus vitamin D 50,000 units weekly for 12 weeks and then the above factors were again checked. Data analysis was done using SPSS statistical software (version 22) and Mann-Whitney and Chi-square tests. P<0.05 was considered statistically significant.

: The mean of FSH, TG, HDL, and vitamin D factors after the intervention significantly increased compared to before the intervention (p<0.05). However, the mean of FBS and HOMA IR factors reduced after the intervention compared to before the intervention, and a statistically significant relationship was observed (p<0.05).

The use of vitamin D in PCOS patients can have an effect on laboratory indices such as FBS, HOMA IR, FSH, TG and HDL.

Transferring a patient from the intensive care unit to the general ward is an anxiety-inducing process that is associated with feelings of insecurity, discomfort, dependency, and increased need. The most important goal of any care program is to satisfy the patient's needs and create a feeling of comfort. The aim of this study was to determine the effect of designed transitional care program on anxiety and general comfort of the patients undergoing coronary artery bypass graft during transfer from open-heart surgery intensive care unit to general ward.

This study was a non-randomized clinical trial with a control group which included 62 patients who were candidates for transfer from the open-heart surgery intensive care unit of Imam Khomeini Hospital in Tehran to the general ward in 2021. The patients were selected by convenient method. The control group received the routine care and were followed up. The experimental group pursued the designed transitional care program in addition to routine care. This program had 4 dimensions: 1-waiting for transfer, 2-support, gradually reducing dependence and increasing independence, 3-communication and strengthening the care triad, and 4-continuity of integrated and need-based care which was implemented by selected and trained nurses in cooperation with the researcher, physician, patients and families for 5-7 days.  Spielberger's anxiety Questionnaires and general comfort scale were completed before the transfer and on the day of the patient's discharge. Using SPSS version 26, the results were analyzed by Fisher's exact, Chi-square, paired and independent t-tests at a significance level of 0.05.

The results showed that the designed transitional care program could significantly reduce anxiety and increase the general comfort of the patients undergoing coronary artery bypass graft (p≤0.000).

Considering the impact of the intervention on the variables under study, use of the designed program as a suitable care program during patient transfer can be suggested.

The main care need of patients with myocardial infarction (MI) is continuous care, presenting an important challenge in the field of nursing care. Therefore, This study aimed to evaluate the effect of nurse-led home-based cardiac rehabilitation on adherence to therapeutic regimens in patients with MI.

Methods & Materials: 

In this randomized clinical trial study, 80 eligible patients were selected through convenience sampling from selected hospitals affiliated with Tehran University of Medical Sciences in 2020-2021. Subsequently, they were randomly allocated to either the intervention or control groups. The control group received routine education upon hospital discharge, whereas the intervention group participated in a nurse-led cardiac rehabilitation program conducted both in-person at home and online, comprising four 90-minute sessions once a week, and were monitored for two months. Participants completed socio-demographic and treatment compliance questionnaires before and three months after the intervention. The collected data was analyzed using descriptive and inferential statistics with SPSS software version 20.

Both groups were homogeneous in most demographic variables (P>0.05). The mean and standard deviation of treatment adherence scores before the intervention in the intervention and control groups were 70.82±7.91 and 67.94±11.20, respectively (P=0.015). After the intervention, these values changed to 75.10±6.13 and 68.77±10.12, respectively, with a statistically significant difference observed between the two groups (P<0.001).

The results revealed that nurse-led home-based cardiac rehabilitation was effective in enhancing treatment adherence. Therefore, it is suggested that cardiac rehabilitation care be consistently extended to the home setting.

Disabled veterans with lower limb amputation are at risk of cardiovascular disease 2 to 3 times more than healthy counterparts due to physical problems and immobility. Exercise is an effective intervention in reducing cardiovascular diseases in different groups. The purpose of this research was to investigate the effect of 12 weeks of aerobic and combined upper-body exercises on cardiovascular risk factors of disabled veterans with lower limb amputation.

In this clinical trial, 45 disabled veterans with lower limb amputation were randomly divided into 3 groups of aerobic exercise, combined exercise, and control. The exercise groups received the desired intervention 3 sessions every week for 12 weeks by observing the overload principle in the duration, volume, and intensity. Measurements of body composition, metabolic indices, and inflammatory indices (C-reactive protein [CRP], interleukin 6 [IL-6], and vascular cell adhesion molecule [V-CAM]) were performed before and after the interventions. All statistical analyses were performed using SPSS-25 software at a significance level of P≤0.05. One-way analysis of variance, Tukey's post hoc test, and paired-sample t-test were used for intragroup and intergroup comparisons.

A significant improvement was observed in weight, body mass index, blood sugar, cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, CRP, and IL-6 in the aerobic and combined training groups, compared to the control group (P≤0.05). A significant improvement was observed in the V-CAM only in the combined training group, compared to the control group (P=0.018). No significant changes were seen in aspartate transaminase and alanine transaminase after any of the interventions (P≥0.05).

For disabled veterans with lower limb amputation, aerobic and combined upper-body exercises can have numerous benefits for the prevention of cardiovascular diseases through the improvement of cardiovascular risk factors.

Dysmenorrhea is a common, painful, and debilitating problem of personal activity with psychological symptoms of anxiety and distress. The present study was performed with aim to investigate the effect of Mandela therapy on anxiety, pain intensity, and distress in primary dysmenorrhea.

This randomized clinical trial study was conducted in 2022 on 80 university students in Arak city who had a pain intensity score of 4 to 8. People were placed in the intervention and control groups. The intervention group painted the mandala for five days in two menstrual cycles. The questionnaires of Spielberger's anxiety, Moos menstrual distress, and numerical pain measure were completed by two groups before and after two intervention periods. Data were analyzed using SPSS statistical software (version 28) and Fisher's exact, independent t and paired t, and Mann-Whitney and Wilcoxon tests. P<0.05 was considered statistically significant.

Although the mean score of dysmenorrhea distress after the intervention had a significant decrease in the intervention group (35.76±8.18) compared to the control group (40±7.93) (d=0.645, p=0.01), but the reduction in mean pain intensity in the intervention group (5.82±2.08) was not significantly different compared to the control group (6.45±1.96) (p>0.05). Also, there was no significant difference between the mean of trait and state anxiety in the two groups after the intervention (p>0.05).

Mandala therapy can be effective in reducing the distress caused by primary dysmenorrhea.

Any treatment method, material, symbol, ritual, or word that has an indirect or non-specific effect is called a placebo or sham. A placebo is described as an ineffective substance, such as injecting saline or a sweet pill, or simulating a treatment that may not have a direct effect on a particular variable but can improve the symptoms of a disease. The term "placebo effect" refers to any therapeutic effect due to the use of a placebo agent, although that agent has no specific biological effect (1). Placebo effects and favorable outcomes resulting from the patient's expectation of treatment should be considered a powerful tool for treatment. In addition, the collaboration between therapist and patient creates the basis for placebo effects (4). However, patient expectations and the patient-therapist relationship, as well as the history of previous treatments, can also have adverse effects and impair treatment. Adverse effects, as opposed to placebo effects, are called nocebo effects (6).Placebo needs different mediators to work. The central nervous system (CNS) is the main station and physiological mediator of placebo effects through memory and learning. Commands related to the sensory, motor, automatic, and immune systems are issued from this station. People have certain individual traits that enable them to respond more or less to a specific stimulus (14). Different mechanisms are described for both placebo and nocebo effects. The characteristics of the treatment environment can act as a conditioned stimulus and evoke a therapeutic effect in the absence of the active therapeutic agent. The conditioned response can also be generated as a nocebo effect. For example, nausea can recur when a patient observes an environment where he or she has undergone chemotherapy in the past. Associate learning, which creates a placebo effect, can be achieved through conditioning. While the relative role of conditioning is not clear, conditioning is an important unconscious mechanism, especially for placebo effects on the immune or endocrine system (21). In addition to conditioning, expectation is also influential as a cognitive issue. The patient consciously predicts the outcome of treatment, positively or negatively (15). Expectation is affected by a person's emotional evaluation of the situation, such as fear, anxiety, or expectation of reward. However, the patient's previous experiences or emotional factors can have a positive or negative placebo effect (24). The computational and mindset models are the other psychological mechanisms behind placebo effects. The difference in the amount and accuracy of expectations that affect the strength of placebo effects in the field of pain can be explained by the Bayesian computational model based on a predictive coding framework (27). Mindsets are frameworks that lead people to shape associations or beliefs about situations or experiences (4). Research on the effect of mindsets on stress response has shown that using the physiological capacity of stress responses to improve performance and cognitive capability, instead of negative perceptions of stress, leads to a more adaptive cortisol state. That means a less cortisol for those with a high cortisol response and a high cortisol for those with a lower cortisol response to stress (26).The results of research related to placebo show that it calms down patients, prevents the prescription of unnecessary drugs, and is used as a complementary therapy. The purpose of using a placebo is not necessarily to deceive. Placebo may thus be an effective treatment; not using it can even be unethical (1). Research in the field of placebo has been conducted for various conditions. High placebo response rates have been reported for Parkinson's disease. Numerous studies have been conducted to investigate the neurobiological basis of placebo responses in Parkinson's disease. It has been determined that the improvement in mobility in these patients is due to the release of dopamine and the activation of the entire pathway from the substantia nigra to the striatum. This can be obtained by stimulating the subthalami region and using a placebo. In addition, the extent of the placebo effect depends on the expectation of recovery, which in turn is associated with the release of dopamine (35). Researchers have also reported placebo-induced improvements in patients with multiple sclerosis (37), epilepsy (38), and depression (19).The purpose of a placebo in clinical trials is exactly the opposite of that in clinical conditions. That is, to limit and reduce the placebo effect as much as possible in order to isolate the pure effect of a particular treatment. Research into placebo mechanisms has at least two important implications for clinical trials: one is to design protocols to circumvent the need for placebo groups. The other is to re-evaluate the methodology of clinical trials. In fact, patient expectations are usually uncontrollable. However they have the potential to affect both the placebo group and the active treatment group distinctly. As a result, attempts to isolate the pharmacodynamic effects would be impossible (41). In clinical trial studies, the adverse effects observed in the active treatment group and the placebo group were often influenced by non-specific factors. The rate of adverse effects reported in placebo groups in clinical trial studies can be quantified using a systematic review. Participants in a double-blind randomized clinical trial know that they will receive either an active drug or a placebo and are aware of any adverse effects they may experience. This information is contained in the informed consent form and provided through instructions from the examiner. Informing participants about possible adverse effects they may experience significantly impacts their expectations (14). The patient's belief regarding allocation to an active treatment group or a placebo group may be more effective than the active drug itself. This is the case in surgery for Parkinsonian patients (33). However, patient expectations have not yet been assessed in a clinical trial or included in the analysis. In routine clinical treatments where a known drug is given to patients, the efficacy of the drug is due to a combination of a nonspecific placebo effect and a biologically active effect. In double-blinded placebo-controlled trials, a direct biological effect is assumed to be the difference between the active and placebo groups. However, because the direct biological and nonspecific effects of placebo may not be solely additive, it is not easy to draw conclusions from double-blind placebo-controlled trials (10). Informed consent may alter the effectiveness of a placebo compared to an active agent in a situation where medications are prescribed to patients without providing information related to the study (45). The placebo effect may be very large for non-blinded interventions. This may lead to an efficacy paradox (46). This happens, for example, when a treatment is effective compared to a drug but has little therapeutic effect compared to a placebo. However, all treatments must meet a high standard to demonstrate their advantage of treatment over the control group. This may occur in surgeries in which nonspecific beneficial effects are prominent, but sham surgery is not used as a control. The same is true for other methods in which blinding is not possible, such as in the case of acupuncture, in which nonspecific effects may be part of the treatment (47). While it is very important to have a consistent control group with expectations with an active intervention, designing an ideal control group for specific interventions, such as psychological and behavioral interventions, may be difficult or impossible. Therefore, knowing the effects of placebo and their biological infrastructure, and considering them in clinical trials, helps to better interpret clinical trials.Various methodological factors may confound placebo effect studies when analyzing and interpreting the results of clinical trials. This means that placebo effects do not include methodological factors that reflect improvement, because these factors are not related to the active change of the measured variable. These factors, including the Hawthorne effect, regression to the mean, therapist, and observer bias, can distort the results of placebo studies. Ignoring these factors leads to misinterpretation of the results of studies related to the placebo effect. In designing randomized clinical trials, therefore, having a control group without intervention and perhaps measuring expectancy are vital elements that can help isolate placebo effects from these confounding factors.In conclusion, the placebo and nocebo effects are complex phenomena that encompass the psychological, biological, neurological, and individual dimensions of human physiology and behavior. The concepts and mechanisms of placebo and nocebo effects can be described by different models and frameworks. Understanding the effects of the placebo can help physicians, therapists, and healthcare providers to improve clinical situations and environments for patients by providing positive expectations through conditioning. On the other hand, limiting the placebo effect as much as possible is recommended in designing clinical trials in order to isolate the net effect of a given treatment.

Epidemic keratoconjunctivitis is a type of conjunctivitis caused by adenoviruses that can spread rapidly through direct and indirect contact. The aim of this study was to evaluate the therapeutic effects of povidone-iodine 0.4% and 0.2% in the improvement of the symptoms and signs of patients with epidemic keratoconjunctivitis.

This clinical trial study included 60 patients with a mean age of 27.8±8.4 years who met our inclusion criteria.The patients were randomly divided into three groups. The first group received povidone-iodine 0.4% and betamethasone 0.1% eye drops the second group received povidone-iodine 0.2% and betamethasone 0.1% eye drops and the third group received betamethasone 0.1% eye drop.  Follow-ups visits were on the first, fourth, seventh and tenth days after starting treatment. Parameters examined at each examination were hyperaemia, mucopurulent discharge, eyelid edema, hemorrhage, and subepithelial infiltration.

The results showed significant differences in the mucopurulent discharge among the treatment groups on the fourth day (P = 0.005) and also on the seventh day (P = 0.001) of the examination. There was no significant difference among the 3 groups in regard to sub-epithelial infiltration on the tenth day after treatment (P = 0.287).

Based on the results of this study, povidone-iodine was more effective than steroids alone in relieving some of the signs of EKC, such as mucopurulent discharge.