Study design, area and period
Institutional based cross-sectional study was employed from November 1, to December 30, 2018. Study participants were recruited consecutively until the estimated sample size fulfilled. The study was conducted at Yirgalem general hospital, which is found in Yirgalem town. The hospital is located south of the national capital Addis Ababa and southeast of regional capital Hawassa. It served about 65,222 patients in 2017. The hospitals provide different services like surgical service, medical, Obstetric and gynecological, pediatric, orthopedic and Emergency. The numbers of patients who undergo surgical procedure in each unit differ according to the extent of procedure to be done, flow of patient, availability and function of surgical equipment. The hospital provides a number of surgical therapies for the patient such as, major surgery, minor surgery, obstetric and gynecological surgery etc.
Source and study population
The source populations were all patients diagnosed and scheduled for elective surgery in Yirgalem general hospital. The study population consisted of adult patients scheduled for elective surgery at Yirgalem general hospital that were available during data collection period.
The study unit was individual patient diagnosed and scheduled for elective surgery in Yirgalem general hospital.
Inclusion and exclusion criteria
The study included all adult patients with age greater than 18 years who were scheduled for elective surgery during the study period. Patients with known anxiety disorder, unable to communicate and took any type of anxiolytics were excluded from the study.
Sample size determination and sampling technique
Single population proportion formula was used to calculate the sample size. Prevalence of preoperative anxiety 59.6% was taken from study done in Gondar hospital, northwest Ethiopia 2017 . Also, 95% CI and 5% marginal error were the assumptions considered.
n = 370 surgical patents, adding 10% non-response rate, the final sample size will be 407.
Data collection instrument
The data collection tool for the study has four parts. The first part of the tool contains questions on socio-demographic and clinical factors, the second part contains questions to asses social support of study participants, the third part assess the possible causes of preoperative anxiety and the fourth part is state-trait anxiety inventory (questionnaires): STAI Form Y-1 and STAI Form Y-2 questionnaire (Additional file 1).
Data collection tools on preoperative anxiety were adapted and modified from validated questionnaire used on other study . The questions and statements were grouped and arranged according to the particular objectives that it can address based on experts comments.
Level of anxiety and need for information about surgery and/or anesthesia were assessed with the state trait anxiety inventory scale (STAI). The STAI was suitable for individuals who are greater than 18 years old. The STAI-Y Form is the definitive instrument for measuring anxiety in adults. It clearly differentiates between the temporary condition of “state anxiety” and the more general and long-standing quality of “trait anxiety”. The STAI has 40 questions with a range of four possible responses to each.
The State Anxiety Scale (STAI Form Y-1) consists of 20 statements that evaluate how the respondent feels “right now, at this moment”. The Trait Anxiety scale (STAI Form Y-2) consists of 20 statements that evaluate how the respondent feels “generally”. In responding to the STAI-Anxiety scale, the subjects choose the number that best describes the intensity of their feelings: (1) Not at all, (2) somewhat, (3) moderately and (4) very much. In responding to the T-Anxiety scale, subjects rate the frequency of their feelings on the following four-point scale: (1) almost never, (2) sometimes, (3) often and (4) almost always. Scores for both the S-Anxiety and the T-Anxiety scales can vary from a minimum of 20 to a maximum of 80. The sum of the scores on all items constitutes the individual’s score .
Data collection technique
Patients who were diagnosed and scheduled for elective surgery interviewed using interviewer administered technique. The data was collected by two trained psychiatry nurses.
Data quality control measurement
The data collection tool was pre-tested on 5% of patients who were diagnosed and scheduled for elective surgery in Adare hospital to check the clarity of the tool and identify any confusing or any vague questions. The data collection was done under close supervision by research team. Completeness of data was checked daily and coded before data entry.
The completed questionnaires were checked for inconsistencies and missed values. Incomplete questionnaires were excluded from the analysis. Before data entry, appropriate coding and editing was performed. After data entries checked, the analysis was performed using SPSS version 22 software. Descriptive statics such as percentage and frequency distribution for different characteristics was used in data. Common descriptive statistics were considered as per variables of interest. Bivariate and multivariate logistic regression analysis was performed. The strength of the association was presented using AOR with 95% confidence interval and p-value < 0.05 was considered as statistically significant.
Anxiety: is state of feeling of an unlikable disturbing experience of the respondents with STAI score of > 44 and above, and those who scored less than 44 don’t have preoperative anxiety. Substance use: is improper usage of any type of psychoactive chemicals within the last 3 months.