Accuracy and reliability of palpation and percussion for detecting hepatomegaly: a rural hospital-based study Rajnish Joshi, Amandeep Singh, Namita Jajoo, Madhukar Pai,* S P Kalantri Department of Medicine, Mahatma Gandhi Institute of Medical Sciences, Sevagram 442 102, Maharashtra; and *Division of Epidemiology, University of California at Berkeley, Berkeley, CA 94720, USA Background: Palpation and percussion are standard Although many physicians believe that physical bedside techniques used to diagnose hepatomegaly. examination can accurately identify hepatomegaly, some Ultrasonography is a noninvasive and accurate method published reports suggest that physical signs lack accu- for measurement of liver size, but many patients in racy and reliability.1,2,3 To our knowledge, no study from developing countries have limited access to it. We India has evaluated the accuracy of physical examina- compared the accuracy of palpation and percussion tion in the assessment of enlarged liver. We conducted in a rural population in central India, using this study to determine how accurately doctors can ultrasonography as a reference standard. Methods: distinguish an enlarged liver from a normal sized one, The study design was a blinded, cross-sectional analysis and how often they agree with one another while as- of a hospital-based case series. Three physicians, sessing liver size. blind to clinical data and to each others results, independently used palpation and percussion to detect Methods hepatomegaly. Diagnostic accuracy was measured by We enrolled consecutive patients admitted to the Medi- computing sensitivity, specificity, and likelihood ratio cine wards between February 1 and 15, 2003. Patients values. Inter-physician agreement was assessed using with pleural diseases (effusion or pneumothorax) or the kappa statistic. Results: Of the 180 study patients, chronic obstructive airway disease were excluded. Writ- 36 (20%) had enlarged liver on ultrasonography. The ten informed consent was obtained from all patients. likelihood ratios for findings at both palpation (2.2, Three physicians with varying levels of training in 3.0, and 2.5 for the three physicians, respectively) internal medicine (NJ, AS and RJ, who graduated in and percussion (1.1 for all three physicians) as 2002, 1999 and 1996, and are referred to as Physicians 1, predictors of true hepatomegaly were low. The kappa 2 and 3, respectively) evaluated patients sequentially. values for inter-observer agreement between three The interval between the first and third physician’s ex- physicians for the presence of hepatomegaly at amination ranged between 10 minutes and two hours. palpation (κ=0.44-0.53) and percussion (κ=0.17-0.33) Before the study began, the three physicians agreed on were low, indicating poor reliability of these techniques. a standardized examination technique, and an experi- Conclusion: Clinical assessment of hepatomegaly by enced physician (SPK), reviewed their bedside techniques. palpation and percussion lacks both accuracy and The study population consisted of patients with hepatic reliability. [Indian J Gastroenterol 2004; 23:171-174] diseases (hepatitis, alcoholic cirrhosis, and hepatoma) Key words: Likelihood ratio, palpation, percussion, as well as non-hepatic diseases (congestive heart fail- predictive value ure, malaria, sepsis, typhoid fever, pneumonia, snake bite, stroke and pulmonary tuberculosis). See editorial on page 163 In each patient, the physicians identified the acromio- and sternoclavicular joints by palpation and marked the hysicians routinely use palpation and percussion for midpoint of a line joining these two points (mid-clavicu- detecting enlarged liver. Although ultrasonography P lar point). A vertical line was drawn from the mid-clav- provides an accurate and noninvasive test for detecting icular point to the mid-inguinal point, and was defined hepatomegaly, patients in developing countries, particularly as the midclavicular line (MCL);4 all clinical as well as in rural settings, often have limited access to it. Thus, sonological measurements were done with reference to clinicians in resource-limited settings often rely on physical this line. Each of the three physicians palpated and examination to detect hepatomegaly. According to our percussed the liver and recorded his findings as pres- hospital records (unpublished data), about 15% of ence or absence of palpable liver edge, and of hepatome- hospitalized patients have diseases that are likely to be galy, defined as cranio-caudal dimension of the liver in associated with an enlarged liver, and hence determination the MCL of 10 cm or more on light percussion.5 The of enlarged liver is an important part of clinical physicians were unaware of clinical data and each other’s examination. findings. Copyright © 2004 by Indian Society of Gastroenterology Joshi, Singh, Jajoo, Pai, Kalantri Bedside detection of hepatomegaly Measurement of reference standard Table 1: Characteristics of study population Parameter Hepatomegaly All patients underwent sonography in the Department at ultrasonography p value of Radiology using a high-resolution real-time scanner Present Absent (General Electric), with a 3.5 MHz curvilinear transducer, (n = 36) (n =144) on the same day as clinical evaluation. The sonologist Age [mean (SD)] (years) 45.5 (16.4) 43.7 (14.8) ns* was unaware of clinical history and physical examina- Body mass index tion findings. Hepatomegaly, as diagnosed by ultra- [mean (SD)] (Kg/m2) 20.6 (3.2) 20.2 (3.5) ns* sonography, was defined as vertical height of liver of Number (%) of women 10 (27.7) 60 (41.5) <0.04** 13 cm or more.6 This cut-off point was based on 95th *t test. **Chi-squared test percentile of observations in 840 subjects in a previous Results study.6 A total of 208 patients were admitted to the Medicine Statistical analysis wards during the study period. Eleven patients with Palpation of the liver edge was recorded as a dichoto- pleural disease (n=6) or chronic obstructive airway dis- mous variable. Percussion of liver span (in centimeters) ease (n=5), and another 17 who were too ill to be trans- was recorded as a continuous variable, as also as a ferred to the Department of Radiology were excluded. dichotomous variable (hepatomegaly present or absent) We thus studied 180 patients (70 women); their mean based on the 10-cm cut-off. Point estimates of the fol- age was 44.1 (SD 15.1) years, mean height 1.52 (0.11) m, lowing test properties were calculated for each response, and mean body mass index 20.4 (3.5) Kg/m2. using standard methods, namely, sensitivity, specific- On ultrasonography, the mean liver span in study ity, positive likelihood ratio (LR+) and negative likeli- 7 patients was 11.4 cm (SD 1.7). A total of 36 patients hood ratio (LR–). The precision of these estimates was (20%) had enlarged liver (11 patients had congestive evaluated using 95% confidence intervals. Post-test prob- cardiac failure, 8 hepatitis, 6 cirrhosis of liver, 6 acute abilities were computed from the likelihood ratios and febrile illness, 3 severe anemia, and 2 leukemia) (Table the prevalence of enlarged liver in the population by 1). Thus, our study population had a 20% pre-test prob- using the formula: pre-test odds x LR = post-test odds. ability of having hepatomegaly. κ We used the kappa ( ) statistic to evaluate chance- Liver size on clinical examination varied from 4 cm corrected agreement between pairs of physicians. A kappa to 20 cm with three observers using two methods of value of 0 indicates that the observed agreement is the clinical examination. The accuracy of clinical examina- same as that expected by chance, and that of 1 indicates tion is outlined in Table 2. Finding of hepatomegaly perfect agreement. The following guides were used for either at palpation or at percussion argued only weakly interpreting the kappa statistic: values of <0.20 indi- for the presence of hepatomegaly (LR+ for clinically cated poor agreement, 0.21–0.40 fair agreement, 0.41– palpable liver, 2.2, 3.0, and 2.5 for three physicians, 0.60 moderate agreement, 0.61–0.80 good agreement, and 8 respectively). Similarly, absence of hepatomegaly as judged 0.81–1.00 very good agreement. by palpation and percussion did not reliably rule out Age, body mass index, liver span and gender were hepatomegaly. Thus, the reliability of both palpation of compared between patients with and without hepatome- liver or percussion span in the MCL in diagnosing galy using t test for continuous, normally-distributed hepatomegaly was poor. χ2 variables, test for categorical variables, and Wilcoxon’s Although the percent agreement between the three Mann-Whitney U test for non-parametric variables. STATA physicians for palpable liver edge appeared to be good (Version 8, Stata Corporation, Texas, USA) and PEPI (82% to 84%), the agreement beyond chance was only (Sagebrush Press, Salt Lake City, Utah, USA) statistical moderate (κ statistic 0.44 to 0.53). For percussion find- softwares were used for data analysis. Table 2: Accuracy of detection of liver edge on palpation and of liver span >10 cm on percussion in diagnosing hepatomegaly using ultrasonography as reference standard Physician Sensitivity Specificity LR+ LR– Post test probability (95% CI) (95% CI) (95% CI) (95% CI) Of positive test Of negative test (95% CI) (95% CI) Clinical diagnosis of hepatomegaly using palpable liver edge Physician 1 38.9 (24.1, 55.4) 81.9 (75.0, 87.6) 2.2 (1.3, 3.7) 0.7 (0.6, 1.0) 35.0 (23.9, 47.9) 15.7 (12.4, 19.6) Physician 2 41.7 (26.5, 58.1)