Self-efficacy can be measured as it relates to many things. In your case, the PESQ test is a generalized measure of pain self-efficacy. For example, if you have high pain self-efficacy, you can perform and enjoy activities even when you are in pain. With high pain self-efficacy you feel confident that you'll meet your life goals. Pain won't hold you back.
Level of self-efficacy is linked with how secure you feel, how anxious you are, and how close you get to others in a relationship. Self-efficacy is higher for people who are more secure. People with lower levels of security are more anxious, fearful, and preoccupied. This makes them less able to face and overcome their pain.
People who aren't able to get close to others in relationships have a more difficult time accepting help. Insecure adults are more vulnerable to chronic pain. Studies suggest that treatment to change these variables may be able to help chronic pain patients. Moving toward a secure adult attachment relationship is a good start toward improving pain self-efficacy.