The Influence of Awareness and Data Collection on Clinical Assessments

Date: November 13, 2024 Reference: Lee WH, et al. Study of Pediatric Appendicitis Scores and Management Strategies: A Prospective Observational Feasibility Study. Academic Emergency Medicine. Dec 2024 Guest Skeptic: Dr. Dennis Ren is a pediatric emergency medicine physician at Children’s National Hospital in Washington, DC. He’s also the host of SGEMPeds. Case: A 10-year-old boy presents to the community emergency department (ED) with abdominal pain. It started last night but the pain seemed to worsen this morning. He tells you that it hurts right around his belly button. On examination, he looks uncomfortable but lets you examine his stomach. He winces a little as you press around his belly button and right lower quadrant but is not guarding. He has not had any fevers. His mother asks you, “I had something like this happen to me when I was a child. By the time they figured it out, the doctors told me that my appendix had almost burst! Do you think this could be appendicitis?” Background: Pediatric appendicitis is the most common surgical emergency in children, accounting for a significant proportion of ED visits. Appendicitis occurs when the appendix becomes inflamed, often because of a blockage, leading to infection and potentially life-threatening complications such as perforation. Although the condition is more common in children between the ages of 10 and 20, it can present at any age, making accurate diagnosis in younger populations especially challenging [1]. The clinical presentation of pediatric appendicitis can vary widely. Classical symptoms include right lower quadrant abdominal pain, fever, and vomiting, but these can be absent or altered in younger children, making clinical diagnosis difficult. Furthermore, the differential diagnosis is broad, including conditions such as gastroenteritis, urinary tract infections, and other causes of abdominal pain like constipation. In one study, almost half of these pediatric patients (45%) with abdominal pain were discharged home with “non-specific abdominal pain” [2].   Traditionally, diagnosis relies on a good history, followed by a directed physical examination and appropriate use of diagnostic tests (lab and imaging). Ultrasound is commonly used due to its non-invasive nature, while computed tomography (CT) scans, although more definitive, are often avoided in children due to radiation concerns [3].  Some centers are using rapid MRI clinical diagnostic pathways in suspected pediatric appendicitis​ [4,5]. Outcomes of appendicitis largely depend on early recognition and treatment. If left untreated, the appendix may rupture, leading to peritonitis, abscess formation, or sepsis, which significantly increases morbidity. On the other hand, early surgical intervention, typically via laparoscopic appendectomy, results in low complication rates and rapid recovery for most pediatric patients​.  Clinical prediction scores (CPS) exist to help diagnose appendicitis in children. They often consider aspects of the history, physical exam and laboratory values. However, these CPSs are not universally used or validated. Three of these CPSs are the Alvarado score [6], Pediatric Appendicitis Score (PAS) [7], and pediatric Appendicitis Risk Calculator for pediatric EDs (pARC-ED) [8].  We also don’t know how they compare to our clinical gestalt. I remember a case I saw as a resident of a young girl who was sent to the ED for belly pain and to be evaluated for appendicitis. Her exam was unremarkable. She didn’t have a fever. She didn’t look sick. I pressed all over her stomach. I had her jump in the air. I looked for the Rosving’s and Psoas's sign. Everything was negative. Her caretaker also told me that her belly pain was like when she had constipation in the past.  It was my attending, whose Spidey senses were tingling, ordered an ultrasound...ruptured appendix. Clinical Question: Can pediatric appendicitis clinical prediction scores accurately diagnose appendicitis in children and outperform clinician gestalt? Reference: Lee WH, et al. Study of Pediatric Appendicitis Scores and Management Strategies: A Prospective Observational Feasibility Study. Academic Emergency Medicine. Dec 2024 Population: Children aged 5 to 15 years presenting with right-sided or generalized abdominal pain and suspected appendicitis Excluded: abdominal trauma within 7 days of presentation, history of prior abdominal surgery, chronic illness affecting the abdomen (inflammatory bowel disease, chronic pancreatitis, cystic fibrosis, sickle cell anemia), pregnancy, inability to obtain accurate history. Intervention: Use of clinical prediction scores (Alvarado, PAS, pARC-ED) Comparison: Clinician gestalt Outcome: Diagnostic accuracy (AUC, sensitivity, and specificity) Type of Study: Prospective observational study Dr. Wei Hao Lee This is an #SGEMHOP, and we are pleased to have the lead author, Dr. Wei Hao Lee, on the show. Dr. Lee is a pediatric advanced trainee currently working at Perth Children’s Hospital in Western Australia. He is interested in pediatric emergency medicine and clinical research. Dr. Lee is investigating clinical prediction scores in pediatric appendicitis, for which he is undertaking a PhD at the University of Western Australia.  Authors’ Conclusions: “The study identified 30 clinical prediction scores that could be validated in a majority of patients to compare their ability to assess risk of pediatric appendicitis. The pARC-ED had the highest predictive accuracy and can potentially assist in risk stratification of children with suspected appendicitis in pediatric EDs. A multicenter study is now under way to evaluate the potential of these CPSs in a broader range of EDs to aid clinical decision making in more varied settings.” Quality Checklist for Clinical Decision Tools: The study population included or focused on those in the ED. Yes The patients were representative of those with the problem. Yes  All important predictor variables and outcomes were explicitly specified. Yes This is a prospective, multicenter study including a broad spectrum of patients and clinicians (level II). No Clinicians interpret individual predictor variables and score the clinical decision rule reliably and accurately. Unsure This is an impact analysis of a previously validated CDR (level I). No For Level I studies, impact on clinician behavior and patient-centric outcomes is reported.  N/A The follow-up was sufficiently long and complete. Yes The effect was large enough and precise enough to be clinically significant. Yes 10.Funding. Channel 7 Telethon Trust. CAHS Telethon Research Scholarship 11.Conflicts of Interest. None declared Results: They enrolled 481 patients. The median age was around 10 years old, and just over half were male. Most of the children (93%) had bloodwork obtained. Around 75% had ultrasound imaging. Only 3.5% had a CT scan. Around 30% (150/481) had appendicitis, with three children (2%) having a normal appendix on histopathology  They identified 30 CPS in the literature search. They were able to collect the required variables for the CPSs ranging from 52% to 93%. Key Results: The pediatric Appendicitis Risk Calculator for pediatric EDs (pARC-ED) was the best performing CPS with clinical gestalt after blood test results being similar. Primary Outcome: Diagnostic accuracy pARC-ED had an AUC 0.9 (95% CI 0.86-0.94) and an accuracy of 97.5 (95% CI 95.1-98.7) and specificity of 99% Clinician gestalt after blood test results had an AUC 0.88 (95% CI 0.81-0.94) and an accuracy of 91.6 (95% CI 86.1-95) Listen to the SGEM podcast to hear Dr. Lee's response to our five nerdy questions. 1. Excluded Patients: Your study team decided to exclude patients with “chronic illnesses affecting the abdomen.” That included inflammatory bowel disease, chronic pancreatitis, cystic fibrosis, and sickle cell anemia. You also excluded pregnant patients. Why did you decide to exclude these patients from your study? Having not reviewed all the CPSs your study team did, were these populations excluded from those studies as well? Because while these patients may have other reasons to have abdominal pain, they can get appendicitis too! 2. Hawthorne Effect: The treating clinicians filled out a standardized clinical report form looking for data points related to the diagnosis of appendicitis. They were also asked how likely it was that the patient had appendicitis twice during the ED course. How do you think this could have impacted the accuracy of clinical gestalt? 3. Missing Variables: Based on supplemental Table 2, it looks like you were trying to collect 29 variables represented on various CPS. A highly challenging and ambitious task! Your success in collecting these variables ranged from 52% to 93%. How do you think these missing variables could have impacted your results? 4. Diagnosis of Appendicitis: There were many ways that the study team determined the diagnosis of appendicitis.  Histopathological report of acute appendicitis within 30 days of index presentation Operative findings of appendicitis or appendiceal abscess report requiring percutaneous drainage Interval appendectomy performed within 60 days of presentation This can lead to a partial verification bias (referral bias, work-up bias). This happens when only a certain set of patients who underwent the index test is verified by the reference standard (surgery with histopathological report). This can increase sensitivity but decrease specificity. We are curious about the definitions you used, especially the last one with interval appendectomy performed within 60 days. Why did you choose this length of time? It seems long.