Does a Structured Data Collection Form Improve The Accuracy of Diagnosis of Acute Abdomen in an Urban Private Hospital?

Makanga W1, Wasike R1, Saidi H2

1 − Department of Surgery, Aga Khan University Hospital

2 − School of Medicine, University of Nairobi

Correspondence to: Dr. Winston Makanga, P.O. Box 168, 20116, Gilgil, Kenya. Email: wmakanga@yahoo.com

Abstract

Background: Accuracy of initial assessment of acute abdominal pain (AAP) is confounded by subjectivity and multiple etiologies for similar presentation. Standardized forms may harmonize the initial assessment, improve accuracy of diagnosis and enhance outcomes.

Objectives: To determine the extent to which use of a structured data collection form (SDCF) affected the diagnostic accuracy of AAP.

Methodology: A before and after study carried out from October 2011 to March 2012 of patients aged 13 years and older presenting with AAP in the emergency department (ED) of Aga Khan University Hospital, Nairobi (AKUH,N). Patients clerked by ED physicians using conventional history taking and examination between October and December 2011 were compared to a second group clerked after the introduction and use of a SDCF (January – March 2012) for proportion of correct diagnosis at initial encounter. This influence of age, gender and disease type on the impact of the form was evaluated as was the impact of the introduction of the structured forms on time to ED disposition, hospital stay, number and cost of investigations. Data were compiled in MS-Excel spreadsheets and analyzed using SPSS v16. P value of <0.05 was significant

Results: 125 participants were included, 60 in Period 1 and 65 in Period 2. The overall mean age for males was 28 and 34 for females. Patients with surgical abdominal conditions were 21% and 49% for medical conditions. The diagnostic accuracy was 58% and 43% before and after the introduction of the SDCF respectively (p=0.088). For surgical patients, diagnostic accuracy was 77% before and 31% after the introduction of the form (p=0.018).

Conclusions: The structured form did not improve the accuracy of diagnosing the causes of acute abdomen. It had a negative impact on the surgical diagnoses.

Introduction

Acute abdominal pain is a common presentation at hospital casualties with an estimated frequency of 5-10%; with one third of cases severe enough to require hospital admission(1). The challenges in identifying the latter group is compounded by multiplicity of possible etiologies, nonspecific nature of the pain, atypical presentation in up one third of patients and a high rate of inter-observer variations in elicitation of signs (2). Predictably, accuracy rates reported in literature have ranged from 42% to 65% (3,4). Uncertainty in making the initial diagnosis often leads to a ‘shot-gun’ approach in ordering of laboratory and radiologic investigations in emergency departments, a practice that increases costs. Further, uncertainty or missing the diagnoses altogether may lead to increased complications. Rates of perforated appendicitis are markedly increased after day 3 of onset of symptoms of acute appendicitis which in turn influences hospital stays and hospitalization costs (5). Attempts to improve accuracy in the evaluation of AAP have included the use of SDCFs (4,6). A SDCF not only organizes the data collection process but also makes sure that no detail in the history or in the clinical examination is left out (7). Their widespread adoption outside centers in the United Kingdom have been hampered by cost of digitization, learning curve and the view that this is an attempt to dehumanize history taking art (1). We purposed to investigate if the SDCF can improve the accuracy in a non-British resource constrained setting as previously shown.

 

Methodology

This was a quasi-experimental before and after study conducted at the ED of the Aga Khan University Hospital-Nairobi (AKUH, N) which consists of a two bed acute room, six bed observation area and nine consultation rooms and manned by 14 senior house officers. Patients aged 13 years and older presenting with non-traumatic AAP between 1st October 2011 and 31st March 2012 were consecutively recruited by trained triage nurses. Period 1 lasted for 3 months, 1st October to 31st December while Period 2 from 1st January to 31st March.

 

Patients with abdominal surgery in the preceding 3 months, advanced pregnancy (more than 20 weeks), known recurrent abdominal pain and patients with prior investigations from the referring facility were excluded. From an earlier pilot study (unpublished) we had computed an underlying diagnostic accuracy of 40%. We wanted to detect a 25% point increase (averaged from previous studies) in accuracy on introduction of the SDCF i.e. to 65% with a power of 80% and a 95% confidence interval. This yielded a sample size of 120 (60 per period). In Period 1, patients were clerked conventionally followed by diagnosis formulation, ordering of investigations and disposition. In Period 2, a SDCF (Fig. 1) was used. This consisted of a series of specific questions and examination maneuvers with definitive responses that were checked. The doctor used the summed up responses to come up with the most likely clinical diagnosis based on those responses. The proposed diagnosis guided further investigations and ED disposition.

 

The time from initial contact to disposition decision was recorded. The final diagnosis was crafted from the results of the investigations and consultant inputs at follow up after ED disposition. Where the definitive diagnosis could not be verified from the charts, yet the patients improved on medications, the conditions were labeled as non-specific abdominal pain (NSAP).

 

This occurred in 19% (24 out of 125) of the patients. Two interactive training sessions, lasting two hours each, were conducted at the ED to familiarize the physicians and nurses with the use of the SDCF before implementation. The author monitored the initial days of implementation and addressed challenges with accuracy of data entered and completeness of information.

 

The ED initial diagnosis (without the aid of tests) was evaluated for concordance with the definitive diagnosis. This was determined by a definitive investigation (e.g. CT Scan), or laparotomy. If the definitive diagnosis was not found initially and patient sent home, further evaluation proceeded as an outpatient – at the clinic, and a diagnosis made by outpatient tests. Ambiguous cases were determined by a consultant surgeon’s validation of the diagnosis during clinic follow-up.

 

This diagnostic accuracy was compared for the period before and after introduction of the structured form and stratified for age, gender and disease type. We also analyzed the impact of the introduction of the structured forms on time to disposition, hospital stay, number and cost of investigations. The Statistical Package for the Social Sciences (SPSSTM) Version 16 was used to analyze the data. Proportions and means were compared using the z test, t test as appropriate.

 

Significance of difference was set at p <0.05. This study was undertaken after approval by the Research and Research Ethics Committees of AKUH, N.

 

Results

From October 2011 to March 2012, a total of 196 patients were eligible for the study, 106 in the Period 1 and 90 in Period 2. In Period 1, 14 participants were excluded; five who were pregnant, two had abdominal malignancies, two were below the age of 13 and one had been assessed initially by a surgeon. In Period 2, 15 participants were excluded; five had pain for more than a week, five presented with predominant symptoms other than abdominal pain e.g. fever, two were known cases of peptic ulcer disease, one had spontaneous abortion, one had recent surgery and one had been seen by a surgeon. In Period 1, 32 participants (30%) had incomplete entry on initial diagnosis or were not followed up to ascertain the final diagnosis. The second period had 10 participants (11%) with incomplete entry on initial and/or final diagnosis. The difference was statistically significant (p=0.006). A total of 125 participants met the inclusion criteria and had complete data, 60 in Period 1 (57%) and 65 in Period 2 (72%).

 

Of the 60 in Period 1, a definitive diagnosis was ascertained in 47 patients while 13 patients had a diagnosis by consensus. In Period 2, 51 had a definitive diagnosis while 14 of the participant had a diagnosis by consensus. Of the 125 patients, 64 were male (35 in Period 1, 29 in Period 2), and 61 were female (31 in Period 1 and 30 in Period 2). The mean age in Period 1 and 2 was 28.25 (27.6 male and 28.8 female) and 34.2 years (34.9 male, 33.4 female) respectively.

The predominant diagnosis was medical in 61 patients, 49%, (28 in Period 1 and 33 in Period 2). Surgical diagnoses constituted 26 patients, 21% (13 in Period 1 and Period 2) and gynaecological conditions were 7% (5 in Period 1 and 4 in Period 2). The category of ‘other’ was 29% and constituted the conditions which couldn’t be classified clearly e.g. non-specific AAP and conversion disorder.

A total of 29 (23% of the study) participants were admitted (17 in Period 1 and 12 in Period 2). Of these, 26 underwent surgery (6 and 2 laparotomies in Period 1 and 2 respectively, 11 and 6 appendectomies in Period 1 and 2 respectively). There were 2 negative appendectomies (all in the first period and no negative laparotomy in both periods. One cholecystectomy was done in Period 2. Three of the admitted patients in the Period 2 did not have surgical intervention.

 

The mean eme