Background and first results about methodological characteristics of the Aachen Life Quality Inventory

Health-related quality of life has become an important criterion for assessing disease impact and treatment outcome. Therefore, we developed a questionnaire called Aachen Life Quality Inventory (ALQI) for the use in neurosurgical patients with brain damage. The ALQI is derived from the German version of the Sickness Impact Profile (SIP). The 117 items are formulated on a concrete behavioral level covering the following dimensions of health-related quality of life: 1. activation 2. mobility; 3. house-work 4. social contact; 5. family relations; 6. ambulation; 7. work; 8. free-time activities; 9. autonomy; 10. communication; 11. cognitive capacity. As in the SIP, a summary score of total impairment (ALQI Total score), a summary score covering the psycho-social dimension (ALQI Psycho-social score) and a summary score covering aspects of physical functioning (ALQI Physical score) can be calculated. The ALQI consists of a self-rating and a parallel proxy-rating version. The ALQI was validated and psychometrically verified using the data of as yet 231 neurosurgical patients with brain damage of mixed etiology (subarachnoid hemorrhage, closed-head injury, benign brain tumors). Internal consistency (Cronbach's Alpha) ranged from .68 to .91 for the subscales, while it was .97 for the whole instrument, .94 for the psycho-social and .93 for the physical score. The internal consistency for the subscales of the proxy-rating version of the ALQI ranged between .77 and .92, while it was .97 for the whole inventory and .94 for the psycho-social and the physical scores., respectively. Examination of construct validity revealed substantial correlations with a wide range of relevant neurological, neurosurgical and neuropsychological parameters. Beyond other findings, substantial associations emerged with several neuropsychological tests (r=.30 to r=.50), the Glasgow Outcome Scale (r=.39; p<.00) and in patients after subarachnoid hemorrhage with the Hunt&Hess grading (r=.28; p<.001). According to these results, the ALQI promises to become a valid and reliable means for assessing quality of life in patients with brain damage. Nevertheless, further analyses using larger patient samples and with particular emphasis on the investigation of the retest-reliability and the prognostic validity are called for in the future.