Patients with histologically proven NFA were eligible for participation in this study if they were between 20 and 70 years of age and if the interval between their last treatment (RT or surgery) and the quality-of-life assessment was at least 12 months. Both surgery and RT were performed in the University Medical Center Groningen, which is a large tertiary referral centre for patients with pituitary pathology. To assure accuracy and completeness of our data collection, patients were only recruited for participation if they were still actively followed at our endocrine outpatient clinic. All patients included in this study received surgery as primary treatment, in some cases followed by a second surgical procedure if a large remnant accessible for surgery persisted. Radiotherapy was given postoperatively to patients with a remnant or after evidence of regrowth. Patients with NFA were retrospectively identified by reviewing several different hospital databases on surgery, radiotherapy, and diagnoses at the endocrine clinic. Thus, a total of 90 eligible patients could be identified who received primary surgical treatment for NFA in our hospital between January 1963 and January 2005.
Questionnaires on quality of life and cognition, use of medication, presence of co-morbidity, and social status were sent to all patients by mail. Use of medication and presence of comorbidity was also confirmed by investigation of the medical charts. Labora-tory results from the last visit (i.e.,< 1 year earlier) to the outpatient clinic were used. Written informed consent was obtained from all subjects.