Yes, solving previous years' question papers for UPSC Medical Science Optional subject can be beneficial for improving decision-making skills. Here's how:

1. Familiarity with Exam Pattern and Question Types:
- By solving previous years' question papers, you will become familiar with the exam pattern and the types of questions asked in the UPSC Medical Science Optional subject.
- This will help you understand the structure of the exam and prepare accordingly, making it easier for you to make decisions about time management and question selection during the actual exam.

2. Identifying Important Topics and Concepts:
- Going through previous years' question papers will give you an idea of the important topics and concepts that are frequently asked in the exam.
- This will help you prioritize your study material and focus on the key areas, enabling you to make informed decisions about what to study and what to skip.

3. Enhancing Problem-Solving Skills:
- Solving previous years' question papers will improve your problem-solving skills as you will encounter a variety of complex and challenging questions.
- This will enhance your ability to analyze and interpret information, enabling you to make effective decisions while solving problems during the exam.

4. Time Management:
- Practicing previous years' question papers will help you develop effective time management skills.
- By solving questions within a given time limit, you will learn how to allocate time to each section and make decisions about when to move on to the next question.
- This will ensure that you complete the exam within the given time frame and maximize your chances of scoring well.

5. Confidence Building:
- Solving previous years' question papers will boost your confidence as you become familiar with the exam format and gain experience in answering questions.
- This will help you make confident decisions during the exam, such as choosing the most appropriate answer or eliminating incorrect options.

Conclusion:
Solving previous years' question papers for UPSC Medical Science Optional subject is an effective way to improve decision-making skills. It provides familiarity with the exam pattern, helps identify important topics, enhances problem-solving abilities, develops time management skills, and boosts confidence. Regular practice of these papers will greatly contribute to your overall preparation for the UPSC exam.