Comparison of resident performance in interpreting mammography results using a probabilistic or a natural frequency presentation: a multi-institutional randomized experimental study.

BACKGROUND: Residents are being increasingly challenged on how best to integrate diagnostic information in making decisions about patient care. The aim of this study is to assess the ability of residents to accurately integrate statistical data from a screening mammography test in order to estimate breast cancer probability and to investigate whether a simple alteration of the representation mode of probabilities into natural frequencies facilitates these computations. METHODS: A multi-institutional randomized controlled study of residents was performed in eight major hospitals in the city of Athens. Residents were asked to estimate the positive predictive value of the screening mammography test given its sensitivity and 1-specificity as well as the prevalence of breast cancer in the relevant population. One version of the scenario was presented in the single-event probability format that is commonly used in the medical literature, while the other used the natural frequency representation. The two questionnaire versions were randomly assigned to the participants. RESULTS: Out of 200 residents, 153 completed and returned the questionnaire (response rate 76.5%). Although more than one-third of the residents reported excellent or close to excellent familiarity with sensitivity and positive predictive value, the majority of responses (79.1%) were incorrect. However, a significantly higher proportion of residents in the natural frequency group (n = 88) selected the correct response compared with residents (n = 65) in the single-event probability group (28.4% vs 10.8%; 95% confidence intervals of the difference between the two proportions = 5.6-29.7%; P < 0.01). DISCUSSION: Residents more often correctly understand test performance accuracy when test characteristics are presented to them as natural frequency representations than the more common approach of presenting single event probabilities. Educators and journal editors should be aware of this facilitative effect.

Assessment of cognitive biases and biostatistics knowledge of medical residents: a multicenter, cross-sectional questionnaire study.

PURPOSE: The aim of this study is to determine the perceived familiarity of medical residents with statistical concepts, assess their ability to integrate these concepts in clinical scenarios, and investigate their susceptibility to the gambler's fallacy and the conjunction fallacy. METHODS: A multi-institutional, cross-sectional survey of Greek medical residents was performed. Participants were asked to indicate their familiarity with basic statistical concepts and answer clinically oriented questions designed to assess their biostatistics knowledge and cognitive biases. Univariate, bivariate, and multivariate statistical models were used for the evaluation of data. RESULTS: Out of 153 respondents (76.5% response rate), only two participants (1.3%) were able to answer all seven biostatistics knowledge questions correctly while 29 residents (19%) gave incorrect answers to all questions. The proportion of correct answers to each biostatistics knowledge question ranged from 15 to 51.6%. Residents with greater self-reported familiarity were more likely to perform better on the respective knowledge question (all p<0.01). Multivariate analysis of the effect of individual resident characteristics on questionnaire performance showed that previous education outside Greece, primarily during medical school, was associated with lower biostatistics knowledge scores (p<0.001). A little more than half of the respondents (54.2%) answered the gambler's fallacy quiz correctly. Residents with higher performance on the biostatistics knowledge questions were less prone to the gambler's fallacy (odds ratio 1.38, 95% confidence intervals 1.12-1.70, p=0.003). Only 48 residents (31.4%) did not violate the conjunction rule. CONCLUSIONS: A large number of medical residents are unable to correctly interpret crucial statistical concepts that are commonly found in the medical literature. They are also especially prone to the gambler's fallacy bias, which may undermine clinical judgment and medical decision making. Formalized systematic teaching of biostatistics during residency will be required to de-bias residents and ensure that they are proficient in understanding and communicating statistical information.

The effort-reward imbalance questionnaire in Greek: translation, validation and psychometric properties in health professionals.

OBJECTIVES: The aim of the present study was to translate, adapt and validate the Effort-reward imbalance (ERI) questionnaire in a sample of Greek healthcare professionals. METHODS: An internationally recommended methodology was followed to perform translation of the ERI instrument into the Greek language. The questionnaire was then randomly administered to 600 Greek physicians, nurses, physiotherapists and laboratory staff, and 456 questionnaires with no missing data on the ERI items were returned (76% response rate). Tool validation included assessment of internal consistency, factorial structure, discriminant validity and presence of floor or ceiling effects. Criterion validity was demonstrated by investigating the association of theoretically relevant ERI summary measurements with respondents' self-rated health. RESULTS: The Greek version of the ERI questionnaire showed good psychometric properties. Cronbach's alpha values were 0.79, 0.72 and 0.75 for the three ERI scales of effort, reward and overcommitment respectively. Exploratory factor analysis yielded a 5-factor solution that closely reflected the original theoretical ERI model. Significant associations were found between respondents' age, gender and specific occupation with ERI scores. ERI ratio and "overcommitment" scores in the highest tertiles were associated with elevated odds ratios (OR) of below-average self-rated health (OR=5.38, 95% confidence intervals 1.77 to 16.38, p=0.003, and OR=3.41, 95% confidence intervals 1.39 to 8.38, p=0.007, respectively). CONCLUSIONS: The translated and adapted Greek version is comparable with the original ERI instrument in terms of validity and factorial structure and is suitable for assessment of the psychosocial work environment of Greek healthcare professionals.

Acute cholangitis due to pancreatic metastasis from squamous cell lung carcinoma: a case report and review of literature.

INTRODUCTION: The pancreas is a well-documented but relatively uncommon site of non-small-cell cancer metastases. However, at the time of diagnosis the disease is usually locoregionally advanced, therefore therapeutic management is mostly palliative and symptomatic. CASE PRESENTATION: We report the case of a 77-year-old Caucasian male patient who presented initially with a clinical picture of acute cholangitis approximately 2 years after a left lower lobectomy for a low-grade squamous lung carcinoma. CT scan imaging of the abdomen and chest revealed an abnormal growth of the pancreatic head and distention of both the intra- and extra-hepatic billiary tree, whereas osteolytic abnormalities were observed of the 5th left rib, consistent with secondary deposits. Initially an endoscopic retrograde cholangio-pancreatography (ERCP) and sphincterectomy was performed and a plastic stent was placed in the common bile duct to decompress the biliary tree. Cytological examination of the aspirate collected by FNA of the pancreatic lession under EUS guidance revealed cells consistent with a low grade squamous lung carcinoma. Two months later an open cholecystectomy along with a gastrojejunostomy was performed to relieve the patient's gastric outlet obstruction symptoms. Following remission of the patient's attack of acute cholangitis and excessive vomiting he was released from the hospital and instructed to initiate chemotherapy with vinorelbine. The patient succumbed to disseminated disease almost 5 months later. CONCLUSION: Symptomatic metastatic lesions of the pancreas from squamous cell carcinoma of the lung are infrequent. Typically, the patients remain asymptomatic until their disease reaches a fairly advanced stage and therapeutic options are limited to palliative measures. A high index of suspicion is the only way of early detection and potentially effective treatment for this rare localization of metastatic squamous lung carcinoma.