http://www.measuringimpact.org/home. A website with very similar aims to this one, developed by Nursing, Midwifery and Allied Health Professionals Research Unit at the University of Stirling in Scotland.
www.proqolid.org. A commercial database of around 800 PROMs (mostly clinical).
National Centre for Health Outcomes Development at the University of Oxford Compendium has a series of systematic reviews of PROMs for various long-term conditions.