I disagree. There are many life saving items that could be carried in a PFAK, such as Diphenhydramine (Benadryl), asprin, Epinephrine (Epi-Pen), a perscribed inhaler, CPR mask, Glucose, and other personal medications.

Most bleeding control items, splints, and litters can be improvised in the field, but you cannot make asprin from willow bark in the amount of time that it would be effective, nor could you make an Epi-Pen from duct tape, p-cord, and a tinderquick.

And then to agree with what others have said, what you carry in your head is more important than any thing you could ever put in a kit.

Just my thoughts...