Hi there! There're lots of ways to get high quality backlinks. Firstly, I would not recommend you massively buying backlinks even when people will offer you the lowest price. The thing is they are low-quality and will only harm your website. In order to get decent backlinks, I suggest writing press releases, listing your company in catalogues, creating pages in social media, making publications in niche mass-media blogs, using forums and Q&A platforms etc. And one more tip for you as a medical company - you can become partners with some educational institutions and get .edu link from them (.edu and .gov links have the highest value).
There are many ways to get quality backlinks ---
1. You can do infographic submission. This is an effective way to build quality backlinks.
2. Post quality content and share it with Social Media
3.You can share video and images with social media to get more engagement
4. You can do forum posting and blog commenting