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Development and validation of a severity scale for leprosy type 1 reactions.

Walker SL, Nicholls PG, Butlin CR, Nery JA, Roy HK, Rangel E, Sales AM, Lockwood DN - PLoS Negl Trop Dis (2008)

Bottom Line: Removal of three items from the original scale resulted in better discrimination between disease severity categories.A moderate reaction is a score of between 4.5 and 8.5.A severe reaction is a score of 9 or more.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. Steve.Walker@lshtm.ac.uk

ABSTRACT

Objectives: To develop a valid and reliable quantitative measure of leprosy Type 1 reactions.

Methods: A scale was developed from previous scales which had not been validated. The face and content validity were assessed following consultation with recognised experts in the field. The construct validity was determined by applying the scale to patients in Bangladesh and Brazil who had been diagnosed with leprosy Type 1 reaction. An expert categorized each patient's reaction as mild or moderate or severe. Another worker applied the scale. This was done independently. In a subsequent stage of the study the agreement between two observers was assessed.

Results: The scale had good internal consistency demonstrated by a Cronbach's alpha >0.8. Removal of three items from the original scale resulted in better discrimination between disease severity categories. Cut off points for Type 1 reaction severities were determined using Receiver Operating Characteristic curves. A mild Type 1 reaction is characterized using the final scale by a score of 4 or less. A moderate reaction is a score of between 4.5 and 8.5. A severe reaction is a score of 9 or more.

Conclusions: We have developed a valid and reliable tool for quantifying leprosy Type 1 reaction severity and believe this will be a useful tool in research of this condition, in observational and intervention studies, and in the comparison of clinical and laboratory parameters.

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Related in: MedlinePlus

Test sites on the hands (2 and 10g) and the feet (10 and 300g).
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Related In: Results  -  Collection


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pntd-0000351-g001: Test sites on the hands (2 and 10g) and the feet (10 and 300g).

Mentions: The ulnar and median nerves are examined using a 2 and 10g monofilament at three sites on the palmar aspect of the hand for each nerve (ulnar and median) and the posterior tibial nerves are assessed using 10 and 300g at four sites on the sole of the foot (Fig. 1). A score from 0 to 6 was assigned depending on the ability of the patient to successfully recognise the weighted monofilaments and the number of sites in which they were felt. For example, on the hand if a person could feel the 2g monofilament at the three sites innervated by the ulnar nerve then a score of zero was recorded. If the 2g was felt at two sites and the 10g at the third site a score of one was recorded. If however the 10g monofilament was not felt at one site then a score of 4 was recorded even if the patient was able to feel the 2g monofilament at the other two sites.


Development and validation of a severity scale for leprosy type 1 reactions.

Walker SL, Nicholls PG, Butlin CR, Nery JA, Roy HK, Rangel E, Sales AM, Lockwood DN - PLoS Negl Trop Dis (2008)

Test sites on the hands (2 and 10g) and the feet (10 and 300g).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2596969&req=5

pntd-0000351-g001: Test sites on the hands (2 and 10g) and the feet (10 and 300g).
Mentions: The ulnar and median nerves are examined using a 2 and 10g monofilament at three sites on the palmar aspect of the hand for each nerve (ulnar and median) and the posterior tibial nerves are assessed using 10 and 300g at four sites on the sole of the foot (Fig. 1). A score from 0 to 6 was assigned depending on the ability of the patient to successfully recognise the weighted monofilaments and the number of sites in which they were felt. For example, on the hand if a person could feel the 2g monofilament at the three sites innervated by the ulnar nerve then a score of zero was recorded. If the 2g was felt at two sites and the 10g at the third site a score of one was recorded. If however the 10g monofilament was not felt at one site then a score of 4 was recorded even if the patient was able to feel the 2g monofilament at the other two sites.

Bottom Line: Removal of three items from the original scale resulted in better discrimination between disease severity categories.A moderate reaction is a score of between 4.5 and 8.5.A severe reaction is a score of 9 or more.

View Article: PubMed Central - PubMed

Affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. Steve.Walker@lshtm.ac.uk

ABSTRACT

Objectives: To develop a valid and reliable quantitative measure of leprosy Type 1 reactions.

Methods: A scale was developed from previous scales which had not been validated. The face and content validity were assessed following consultation with recognised experts in the field. The construct validity was determined by applying the scale to patients in Bangladesh and Brazil who had been diagnosed with leprosy Type 1 reaction. An expert categorized each patient's reaction as mild or moderate or severe. Another worker applied the scale. This was done independently. In a subsequent stage of the study the agreement between two observers was assessed.

Results: The scale had good internal consistency demonstrated by a Cronbach's alpha >0.8. Removal of three items from the original scale resulted in better discrimination between disease severity categories. Cut off points for Type 1 reaction severities were determined using Receiver Operating Characteristic curves. A mild Type 1 reaction is characterized using the final scale by a score of 4 or less. A moderate reaction is a score of between 4.5 and 8.5. A severe reaction is a score of 9 or more.

Conclusions: We have developed a valid and reliable tool for quantifying leprosy Type 1 reaction severity and believe this will be a useful tool in research of this condition, in observational and intervention studies, and in the comparison of clinical and laboratory parameters.

Show MeSH
Related in: MedlinePlus