ASSESSING THE RELIABILITY OF ALVARADO SCORING SYSTEM IN PREDICTION OF ACUTE APPENDICITIS.

and Dr. Abdulaziz Altwejri 3 . 1. Undergraduate students at College of medicine, Qassim University. 2. MBBs, MD, SBGS, General surgery consultant, head of general surgery department king fahad specialist hospital-Buraidah. 3. MBBS, general surgery senior specialist, head of A&E department at king fahad specialist hospital-Buraidah. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


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On examination, the patient presents with tachycardia, tenderness in the right lower abdominal quadrant, guarding, and rigidity. The clinical diagnosis of acute appendicitis is based on the history and physical examination. Therefore, there is no specific diagnostic test to confirm the diagnosis of appendicitis. However, the use of urine and blood tests are only to exclude other diseases and give additional evidence to support the clinical diagnosis. (3) Histopathology reports will also establish the diagnosis of appendicitis. To confirm the presence of appendicitis under the microscope, there will be a transmural neutrophilic infiltration. (4) The histologic assessment also defined the difference between endo-appendicitis (neutrophils within mucosa and mucosal ulceration) and peri-appendicitis (inflammation restricted to serosa and subserosa).(4) A scoring system like Alvarado Score has been considered to help in the diagnosis of appendicitis. A recent study estimated that Alvarado scoring system is being most useful in ruling out appendicitis, as Alvarado score below 5 has a sensitivity of 94%-99% for appendicitis not being present.(5) Alvarado score is a 10-point scoring system based on clinical presentations and leukocytosis. The score has six clinical items and two laboratory measurements [ Our study aims to establish the reliability of Alvarado Scoring System at King Fahad Specialist Hospital (KFSH).  5. all medical records before 1/1/2015 and after 1/1/2017 will be excluded.

Sample size determination:-
The data will be collected from all medical records of patients who are diagnosed with acute appendicitis between 01/01/2015 and 01/01/2017 at KFSH in which each file will be chosen unless the files do not match the inclusion criteria.

Study duration and timeline:-
Protocol Development 2 Ethical Clearance 3 Data Collection Data Entry and Data Analysis 5 Manuscript Writing Data collection:-The data will be retrospectively collected from the medical records of the patients who are diagnosed with appendicitis between 1/1/2015 to 1/1/2017 at King Fahad Specialist Hospital in Buraidah. Also, the sample size will be 500 patients files. Then, we will apply the inclusion and exclusion criteria. After that, we will label the selected files numerically from 1 to 500 to keep the identity of the patient anonymous. The alvarado scoring for each patients will be obtained out of 10 points based on signs, symptoms, and leukocytosis by using the data from the medical files (table 1). The probability of the scoring system will be divided according to the result of the score into low, intermediate, and high (table 2). Then, the collected data will be entered into Excel database then transfer to SPSS for statistical analysis. To assess the reliability of Alvarado score we will compare the high probability with positive histopathology findings. The general surgery department staff Dr.Sultan Alsaigh, general surgery consultant, and Dr.Abdulaziz Altwejri, senior specialist, will participate and facilitate the process of taking permission from the head of hospital for the obtained the data.

Statistical analysis:-
Descriptive statistics were used to describe the baseline characteristics of all patients. The mean and standard deviations were reported for continuous variables, frequencies were used for categorical variables. Frequency and percentage of acute appendicitis according to histopathology report in different clinical probability groups determined by ALVARADO score were presented. The sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratios were calculated for patients with ALVARADO score of 7 to 10 and 5 to 10. Data analysis was performed at 95% CI using Statistical Package for Social Science (SPSS), version 20 (IBM, Armonk, NY, USA). Patients with ALVARADO score 7-10, 5-6 and less than 5 were grouped as high, intermediate and low clinical probability respectively. The number and percentage of patients developed acute appendicitis according to histopathology report in high (n = 96), intermediate (n = 70) and low (n =34) clinical probability groups were 93 (96.88%), 66 (94.30%) and 28 (82.35%) respectively. (Table 3) High ALVARADO score (7 -10) yielded sensitivity of .50, specificity of .77 and a positive and negative predictive value .97 and .10 respectively. The sensitivity was increased to .85 and specificity was decreased to .46 when we considered ALVARADO score 5 to 10 for the diagnosis of acute appendicitis. (Table 4)     Discussion:-Acute appendicitis needs surgical intervention and the severity of disease is mainly established by histopathological methods. Therefore, it is critical to correlate surgical intervention to other diagnostic methods to avoid unnecessary surgical intervention. Alvarado is scoring system which is being used to diagnose acute appendicitis and various studies has been carried out to correlate it to surgical intervention [1][2][3][4].This retrospective study was conducted to establish the relevance of Alvarado scoring system to surgical procedures in Buraidah region of Saudi Arabia. Gender, type of surgery, post-operative diagnosis, clinical probability and histopathology were recorded (Table 1).

Results:-
Both laparoscopic and open surgery were performed in male and female patients. On the other hand, the scoring systems such as Lintula, Madan, Ohmann, Eskelinen, De Dombal, and Alvarado are non-invasive and do not require complex practical expertise. Alvarado scoring system (ASS) is mainly focused on clinical and laboratory data of patient [5]. In our study, the male and female ratio was 2.03:1, which is comparable to a few other studies [6][7][8]. Post operative diagnosis of acute appendicitis was observed among 188 patients (94%). Alvarado score was used to characterized patients into three groups: High acute appendicitis group (7≤score≤10), intermediate acute appendicitis group (5≤score≤6), Low acute appendicitis group (5<score). Based on clinical probability, patients were grouped in high, intermediate and low groups (Table 1). Histology also reported the acute appendicitis among 188 patients ( Table 1). The overall negative predictive value for appendectomy was 5.5% in clinical probability, while overall positive predictive value was 95.5%. In a previous study also reported an overall negative and positive value for appendectomy as 7% and 93% respectively [9]. Further, an overall negative and positive values for appendectomy as 10.9% and overall 90.1% has also been documented [10]. In a seminal study, Vukovik etal. also reported an overall negative appendectomy 15.79% and overall positive appendectomy 84.21% [11]. All these data furnished in previous studies are comparable to our results.
Further, a Saudi Arabia based report predicted an overall negative and positive appendectomy values as 11.3% and 89.7%, respectively [6]. The average Alvarado score was 6.42±1.89, which indicated nature of risk among patients and was comparable to another study carried out in Makkah, region of Saudi Arabia [6]. Clinical probability scores 93, 66 and 28 indicated high (96.88%), intermediate (94.30%) and low (82.35%) level of acute appendicitis. This indicates negative predication as compared to histopathological results. Sensitivity and specificity for high Alvarado score (7-10) were 0.50 (50%) and 0.70 (70%), respectively with 2.17 and 0.65 likelihood ratio (LR) for positive and negative test results. The positive LR score and low negative LR score shows that Alvarado score (7-10) is an indicator of high risk of acute appendicitis. However, the specificity and selectivity were quite low from other studies [11,12]. Whereas, the sensitivity and specificity for intermediate to high Alvarado score were 0.85 (85%) and 0.46 (46%), respectively. The corresponding likelihood ratios for positive and negative test results were 1.57 179 and 0.33, respectively. The LR positive score (1.57) and low LR negative score (0.33) indicate a possible correlation to the acute appendicitis. In this range of Alvarado score (5-10). Conclusively, though sensitivity was improved (85%), the specificity did not represent score as good indicator of acute appendicitis.

Limitations:-
The physical examination information written in some of the patients' files weren't complete and had missing information. some physicians weren't able to write a complete abdominal examination report and history report for patients with abdominal pain due to the huge influx of patients in the emergency department.

Recommendations:-
After getting the results of our study, we believed that alvarado score is not a sensitive tool to role out the diagnosis of acute appendicitis although its may help to role in the diagnosis

Ethical part & confidentiality:-
The data will be collected anonymously without any personal identifiers. Also, all the data which will be collected and analyzed, no one can link the results of our study with the personal identities. When the data is collected, we will apply the data to the inclusion and exclusion criteria. Then, the data will be entered into an excel-format file.