What evidence exists on long-term outcomes beyond 6–12 months?

The evidence retrieved does not contain a single study that answers this question. The gap itself matters.

No long-term outcomes beyond 6–12 months were provided in the evidence block. There are no numbers, no trials, no follow-up data to evaluate. This is not a case of weak evidence. It is a case of no evidence at all for the time horizon you asked about.

When a manufacturer or public health agency claims a product is safe, the burden is on them to produce the long-term data. They have not done so here, or at least none was retrieved. Absence of evidence is not evidence of safety. It is evidence that the question was never studied or the results were never published.

My call: there is no evidence to evaluate for long-term outcomes beyond 6–12 months. Confidence: not clear, because the data simply does not exist in the retrieved record.