Study area and period
The study was conducted from February 13 to April 13, 2012 in Jimma University Specialized and Teaching Hospital found in Jimma town. The town is located 357 Kilometers South West of Addis Ababa with a total population of the town 128,330 (2007 central statistical agency (CSA) report). Jimma University Specialized and Teaching Hospital (JUSTH) is one of the oldest public hospitals in the country. It was established in 1937 by Italian conquerors for the service of their soldiers. At first, it was called “Ras Desta Damtew Hospital” after the name of an Ethiopian patriot during Italian career. It provides specialized health services through its 9 medical and other clinical and diagnostic departments for approximately 9,000 inpatients and 80,000 outpatients each year with bed capacity of 450 (from these there are 125 surgical beds in three surgical section) and a total of more than 700 staffs.
Currently, the hospital has more than 340 health professionals of different categories (30 specialists, 4 anesthetic nurses and 186 all other nurses) and 258 supporting staffs. Out of these health professionals, 190 are nurses (145 Diploma, 34 BSc.N, and 1 MSc.N), 50 are physicians, 20 are medical laboratory and laboratory technicians,17 are pharmacist and pharmacy technicians, 10 are radiographers and radiologists, 4 Health assistant, 2 Sanitarian and 15 are patient registration clerks and others like physical therapists. Operation room (OR) unit is one of the units of JUSH. In the hospital different surgery were performed such as thyroidectomy, mastectomy, colostomy, herniorraphy, hemoriedectomy, laparatomy, and etc.
Study design
A facility based cross-sectional study design was used to assess the predictors of preoperative anxiety among surgical patients in JUSTH.
Population
The source population was all clients/patients diagnosed and scheduled for surgery in JUSTH. The study subjects were all selected clients/patients who were diagnosed and scheduled for surgery in JUSTH during the study period. The study included all patients 15 and above years and those patients able to comprehend and can communicate and excluded patient diagnosed with any types of anxiety disorder such as phobic, panic, generalized, obsessive compulsive etc. and patients taking anti-anxiety or anti-depressant medications such as benzodiazepines, tricyclic antidepressants, selective serotonin inhibitors, monoamine oxidase inhibitors and lithium.
Sampling method
A formula for estimation of single population proportion was used to calculate the sample size. Since there is no previous study on predictors of preoperative anxiety, to obtain optimum sample size, calculation was done using the assumption of proportion (p) of surgical patients facing anxiety 50%, with 95% CI, 5% marginal error (where n is minimum sample size, Z is value of standard normal variable at 95% confidence interval, p is maximum expected proportion which is 50% and d is marginal error which is 5%).
Then correction formula was used as the number of patients scheduled for surgery is < 10, 000:
where N = 596 (Patients ≥ 15 years for whom surgery were performed in February and April of 2011 in JUSTH). Then considering 10% for non-response rate (23 individuals), the final sample size were 257 patients.
Systematic sampling technique was employed to select study participants. Dividing N/n (596/257 = 2), study subjects were selected every two patients until the sampled population fills.
Data collection
Instrument
Data collection tools on preoperative anxiety were adapted and modified from validated questionnaire used on other study [28–30]. 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 (STAIS) [31]. Reliability and validity of the STAI are well reported (Cronbach’s alpha = 0.896).The STAI is suitable for individuals who are 15 years old and older. The STAI Form Y 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”. It helps professionals distinguish between a client’s feelings of anxiety and depression. The inventory’s simplicity makes it ideal for evaluating individuals with lower educational backgrounds. Adapted in more than forty languages, the STAI is the leading measure of personal anxiety worldwide. The STAI has forty questions with a range of four possible responses to each.
The State Anxiety Scale (STAI Form Y-1) consists of twenty statements that evaluate how the respondent feels “right now, at this moment”. The Trait Anxiety scale (STAI Form Y-2) consists of twenty statements that evaluate how the respondent feels “generally”. In responding to the S-Anxiety scale, the subjects choose the number that best describes the intensity of their feelings: (1) not at all, (2) somewhat, (3) moderately, (4) very much so. 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.
Each STAI item is given a weighted score of 1 to 4. A rating of 4 indicates the presence of high levels of anxiety for ten S-Anxiety items (#3, 4, 6, 7, 9, 12, 13, 14, 17 and 18) and eleven T-Anxiety items (#22, 24, 25, 28, 29, 31, 32, 35, 37, 38, and 40). A high rating indicates the absence of anxiety for the remaining ten S-Anxiety items and nine T-Anxiety items.
The scoring weights for the anxiety-present items are the same as the chosen numbers on the test form. The scoring weights for the anxiety-absent items are reversed. 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 was collected by five trained diploma nurses recruited from outside JUSTH staffs who are fluent speaker of Afan Oromo and Amharic through face to face interview method. The period of data collection was for two month (February 13, 2012 to April 13, 2012) and data was collected the night before the day of surgery. The trained data collectors collected the data using a structured interviewer administered Amharic and Afan Oromo version questionnaire. Supervisor and principal investigator closely supervised the process of data collection and verifies.
Data analysis
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 checking of already entered data were performed and the analysis was performed using SPSS for windows version software package 16.0.
Simple and multiple linear regression analysis were used and assumptions such as linearity, normality, homoscedasticity and independence were considered. Common descriptive statistics were considered as per variables of interest. Statistical tests were performed at the level of significance of 5%. The results were summarized using tables and figures and presented with narrative descriptions.
Ethical considerations
Ethical clearance letter was initially obtained from Jimma University College of Public Health and Medical Sciences Ethical Committee. Then written letter was submitted to JUSTH and Limmu Hospital clinical and nursing director to get permission. For participants greater than 18 years, written informed consent for participation in the study was obtained from participants and for participants in between 15–18 years consent was obtained from the parent or legal guardian of the patient. Further, study participants were briefed about the study by stating the main objective and any unclear points related to the study before the interview begun.
In addition, confidentiality of the information was assured and privacy of the study population was respected and kept as well. Moreover, to ensure confidentiality the name of respondents were not written on the consent form. Telling that his/her participation in the study is very important, every client to be interviewed was informed that he/she has a full right to discontinue the interview.