Evaluation of the effectiveness of the Indian government's policies to strengthen health warning labels on smokeless tobacco products: findings from the 2010-2019 Tobacco Control Project India Surveys.

There was no significant change in HWL effectiveness following the revision from a symbolic to a pictorial image, but enlarging pictorial images resulted in some improved cognitive and behavioural effects. Results suggested wear-out of HWL salience and that the effectiveness of warnings depends on both their design and time since implementation.