A NEW APPROACH TO THE MEASUREMENT OF QUALITY-OF-LIFE - THE PATIENT-GENERATED INDEX

Quality of life has been defined as ''the extent to which our hopes an d ambitions are matched by experience.'' To improve a patient's qualit y of life through medical care would be to ''narrow the gap between a patient's hopes and expectations and what actually happens.'' Using th e above definition as a conceptual basis, we produced a self-administe red, Patient-Generated Index (PGI) of quality of life. The PGI was com pleted by 359 patients presenting with low back pain. The validity of the measure was assessed by correlating patients' PGI scores with a we ll-validated health profile, the Short-Form 36-item Health Survey (SF- 36), and with their scores on a clinical back pain questionnaire. Step wise multiple regression was then used to model the relationship betwe en the PGI score and the SF-36. Patients' PGI scores showed a high cor relation with SF-36 scales measuring pain, social functioning, and rol e limitations attributable to physical problems, and with the clinical questionnaire. Together with whether a person was retired or not, the se health variables were able to explain 25% of the variance in PGI sc ores. Patient generated index scores were significantly lower in patie nts referred to hospital compared with those managed solely in general practice and tended to reflect the general practitioner's assessment of symptom severity. We conclude that it is possible to construct a qu estionnaire that quantifies the effect of a medical condition on patie nts' quality of life in a way that has meaning and relevance in the co ntext of their daily lives. The PGI has considerable potential for rou tine use in a wide range of clinical conditions for which the measurem ent of outcome has hitherto proved very difficult.