I don't have access to the actual study but I wonder if they had access to any metrics for the individuals that could quantify the intensity of the insomnia. Chronic insomnia/sleep deprivation is already correlated with heart disease. Could it be that the people with worse insomnia were more likely to take melatonin but also more likely to have heart issues due to the insomnia alone?
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I don't have access to the actual study but I wonder if they had access to any metrics for the individuals that could quantify the intensity of the insomnia. Chronic insomnia/sleep deprivation is already correlated with heart disease. Could it be that the people with worse insomnia were more likely to take melatonin but also more likely to have heart issues due to the insomnia alone?