"Philippines has one of the world's lowest suicide rates. What kind of outlook do Filipino's have on mental health that keeps the suicide rate so low?" - u/Vxrtyu

I'm way late but here's a few things, I have taken graduate courses that discussed this (Death and Dying courses, and some sociology on this):

Underreporting as other comments said. It is widely known that suicides are covered up in religious places, especially when suicide is considered an unforgivable sin. Lots of people die because they "had a fall" or "a sad accident."

Lack of means and privacy. Most people want to kill themselves alone. Without much privacy, that isn't easy to do.

In the US, men have a higher suicide rate than women, but women are more likely to attempt suicide than men. Men tend to use more lethal means like firearms, etc. Women tend to use means that aren't as reliably lethal. In the Philippines, there are limited ways to kill yourself in a quick, clean, reliable way. That's what most people want it to feel like. Frankly, the logistics of a quick and easy suicide are not at all easy.

There is also a social and cultural aspect. More social isolation contributes to suicide rates. People in the Philippines are often deeply embedded in relationships with family/friends/etc, and that can make a difference (even if those people are awful and part of the problem to begin with).

Also, remember suicide rates vary across space/time. Some time periods are worse than others. A low suicide rate at some time doesn't mean a society isn't susceptible to suicide as a problem at other times.

Lastly, although suicide is perhaps the most tragic and extreme outlet that people pursue, it is not the "be-all-end-all" sign of a society's social health. To evaluate the health of a society requires considering other issues, such as rates of crime, drug/substance abuse, social isolation, antisocial behavior, etc.