Complex sentence: Studies have shown opioids to be safe when they are used correctly and in the ways that are well understood, however, public health bodies in the United States and Canada have declared opioid use, including accidental addiction and overdosing, to be a public health crisis.
Split into simpler sentences: Studies have shown opioids to be safe when they are used correctly and in the ways that are well understood. However, public health bodies in the United States and Canada have declared opioid use, including accidental addiction and overdosing, to be a public health crisis.