Modification of the Stockholm Vascular Scale

Area of Science:

• Occupational Medicine
• Vibration-Induced Injuries
• Clinical Diagnostics

Background:

• Accurate staging of hand-arm vibration syndrome (HAVS) is crucial for assessing worker health.
• Current staging methods, like the Stockholm Workshop Scale (SWS), have limitations in classifying all individuals.
• Previous modifications to the SWS for specific populations (e.g., coal miners) and proposed changes to Stage 2V require further investigation.

Purpose of the Study:

• To evaluate the impact of proposed modifications to the Stockholm Workshop Scale (SWS) on the classification of hand-arm vibration syndrome (HAVS).
• To assess how different definitions of 'frequent' blanching attacks influence HAVS classification.
• To determine the effect of subdividing Stage 2V on the proportion of unclassifiable individuals.

Main Methods:

• Individuals with HAVS were staged using the SWS with two modified scales.
• Two distinct thresholds for defining frequent blanching attacks (>=3 or >=7 attacks/week) were applied.
• The impact of splitting Stage 2V into 'early' and 'late' categories was analyzed.

Main Results:

• The original SWS left 58% and 31% of individuals unclassifiable based on the two 'frequent attack' cut-offs.
• Modifying the SWS by subdividing Stage 2V significantly reduced unclassifiable cases to 2% and 9%.
• The choice of cut-off for frequent attacks influenced the distribution between Stage 2Vearly (17-42%) and Stage 2Vlate (45-20%).

Conclusions:

• Subdividing Stage 2V of the SWS enhances the ability to classify more individuals with HAVS.
• The proportion of individuals classified into Stage 2V subdivisions is sensitive to the chosen frequency threshold for blanching attacks.
• Caution is advised when using these modified classifications for fitness-to-work decisions due to the variability introduced by attack frequency definitions.