Learn Russian: Эмпатия по отношению к пациентам — это важно.

It is governed by the compound preposition по отношению к (in relation to / towards). The final word of this phrase is the standard preposition к, which always requires the dative case.

Could I just say эмпатия к пациентам instead of using the long phrase по отношению к?

Yes, you can. Эмпатия к пациентам is perfectly natural. Using the full phrase по отношению к makes the statement sound a bit more formal, analytical, or professional, which fits well when discussing medical or psychological standards.

Why do we need the dash and the word это before the adjective?

Since Russian does not use the present tense of the verb 'to be' (is), the dash and the particle это act together as an equals sign to link the subject to its description. It emphasizes that you are defining a concept or stating a general rule.

Since the subject эмпатия is feminine, why does the sentence use the neuter word важно instead of the feminine важная or важна?

When you use the dash plus это structure to evaluate something or state a general truth, the descriptive word defaults to the neuter short form. If you wanted to match the gender of the noun, you would drop это entirely and use the feminine short adjective: Эмпатия по отношению к пациентам важна.