Given the task definition and input, reply with output. Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.

Question: Is traditional couching an effective alternative procedure for cataract surgery in Mali?
Answer: In Mali, two types of providers offer two different interventions to treat cataract-blind persons. This study suggests that the couching method used by traditional healers is relatively expensive and ineffective. It is also potentially dangerous although this study did not address this question specifically. It is important that health policy makers and medical authorities do what they can to prevent traditional healers from performing the couching procedure, as well as informing the population about the existence of a more-effective and safer alternative. However, while more effective and safer, the results obtained by ICCE are not excellent either. Further, it is important to improve the quality of ophthalmic services in order to provide cataract patients with the best, most accessible and least expensive services possible.
no