Comments on Lindberg’s Correction for the Effects of Observer Variation on Probabilistic Diagnosis

1982 ◽  
Vol 21 (03) ◽  
pp. 114-116
Author(s):  
D. J. Spiegelhalter
Keyword(s):  
Numerical Solution ◽  
Data Base ◽  
Observer Variation ◽  
Symptoms And Signs ◽  
Probabilistic Diagnosis

Lindberg [2] proposes an adjustment of a probabilistic system for diagnosis in the light of known observer variation in the eliciting of symptoms and signs. He finds that his proposal leads to somewhat diffident predictions. We show that such an adjustment is only appropriate when the system is implemented with observers who are less reliable than those who created the data-base. In this case, with certain assumptions, an adjustment may be made that is less radical than that of Lindberg. A simple numerical solution for binary symptoms is provided.

Effects of Observer Variation on Performance in Probabilistic Diagnosis of Jaundice

1981 ◽  
Vol 20 (03) ◽  
pp. 163-168 ◽  
Author(s):  
G. Llndberg
Keyword(s):  
Physical Examination ◽  
System Performance ◽  
Transition Matrix ◽  
Bayes Theorem ◽  
Observer Variation ◽  
Kappa Statistics ◽  
Diagnostic Categories ◽  
Number Of Patients ◽  
Probability Transition Matrix ◽  
Probabilistic Diagnosis

A system for probabilistic diagnosis of jaundice has been used for studying the effects of taking into account the unreliability of diagnostic data caused by observer variation. Fourteen features from history and physical examination were studied. Bayes’ theorem was used for calculating the probabilities of a patient’s belonging to each of four diagnostic categories.The construction sample consisted of 61 patients. An equal number of patients were tested in the evaluation sample. Observer variation on the fourteen features had been assessed in two previous studies. The use of kappa-statistics for measuring observer variation allowed the construction of a probability transition matrix for each feature. Diagnostic probabilities could then be calculated with and without the inclusion of weights for observer variation. Tests of system performance revealed that discriminatory power remained unchanged. However, the predictions rendered by the variation-weighted system were diffident. It is concluded that taking observer variation into account may weaken the sharpness of probabilistic diagnosis but it may also help to explain the value of probabilistic diagnosis in future applications.

Inter-observer variation of symptoms and signs in jaundice

2008 ◽  
Vol 1 (1) ◽  
pp. 21-32 ◽  
Author(s):  
A. Theodossi ◽  
R. P. Knill-Jones ◽  
A. Skene ◽  
G. Lindberg ◽  
B. Bjerregaard ◽  
...  
Keyword(s):  
Observer Variation ◽  
Symptoms And Signs

Reliability of History Taking and Physical Examination in Jaundice

1982 ◽  
Vol 21 (03) ◽  
pp. 137-142 ◽  
Author(s):  
C. Helmers ◽  
G. Lindberg
Keyword(s):  
Physical Examination ◽  
Alcohol Intake ◽  
Clinical Signs ◽  
Diagnostic Value ◽  
Observer Variation ◽  
Kappa Statistics ◽  
History Taking ◽  
Palmar Erythema ◽  
Before And After ◽  
Symptoms And Signs

Four observers interviewed and examined 19 jaundiced patients, recording sixteen common symptoms and ten clinical signs that had been defined in advance. Kappa statistics were used for evaluating the data. All studied symptoms and seven signs showed agreement between observers significantly greater than expected by chance. The clinical significance of inter-observer variation was studied in a set of 144 jaundiced patients. The diagnostic value of studied symptoms and signs was calculated before and after correction for inter-observer variation. Only five symptoms: itching, loose bowels, ache, ache/pain description and alcohol intake, and three signs: spider naevi, palmar erythema and ascites retained more than 60% of their diagnostic value after correction for inter-observer variation.

Questions and Answers

2000 ◽  
Vol 5 (2) ◽  
pp. 3-3
Author(s):  
Christopher R. Brigham ◽  
James B. Talmage
Keyword(s):  
Nervous System ◽  
Peripheral Nervous System ◽  
Spinal Nerve ◽  
Sensory Loss ◽  
Residual Symptoms ◽  
Additional Information ◽  
Questions And Answers ◽  
Motor Nerves ◽  
Symptoms And Signs ◽  
Limited Motion

Abstract Lesions of the peripheral nervous system (PNS), whether due to injury or illness, commonly result in residual symptoms and signs and, hence, permanent impairment. The AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) describes procedures for rating upper extremity neural deficits in Chapter 3, The Musculoskeletal System, section 3.1k; Chapter 4, The Nervous System, section 4.4 provides additional information and an example. The AMA Guides also divides PNS deficits into sensory and motor and includes pain within the former. The impairment estimates take into account typical manifestations such as limited motion, atrophy, and reflex, trophic, and vasomotor deficits. Lesions of the peripheral nervous system may result in diminished sensation (anesthesia or hypesthesia), abnormal sensation (dysesthesia or paresthesia), or increased sensation (hyperesthesia). Lesions of motor nerves can result in weakness or paralysis of the muscles innervated. Spinal nerve deficits are identified by sensory loss or pain in the dermatome or weakness in the myotome supplied. The steps in estimating brachial plexus impairment are similar to those for spinal and peripheral nerves. Evaluators should take care not to rate the same impairment twice, eg, rating weakness resulting from a peripheral nerve injury and the joss of joint motion due to that weakness.

Data base or data bias?

1990 ◽  
Vol 45 (5) ◽  
pp. 676-676 ◽  
Author(s):  
Douglas E. Mould
Keyword(s):  
Data Base
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