In this nationwide population-based cohort study, we showed that nearly half the patients who underwent a craniotomy for excision of brain tumors experienced a deterioration in their QOL in the first year after surgery: 595 (12.3%) lost their jobs, 1,329 (27.4%) earned less, and 844 (17.4%) developed new disabilities. Male sex, reoperation, and longer LOS were significantly associated with a higher incidence of QOL deterioration. A deterioration in QOL was associated with a higher risk of 2-year mortality, especially for brain cancer mortality. Interestingly, of the QOL measures which we analyzed, job loss and decreased income were not associated with mortality, while newly acquired disability was.
In this study, brain disability had the highest proportion among the newly acquired disabilities (764/844, 90.5%) in the patient cohort. It has been reported that of the neurological sequelae observed among brain tumor survivors, cognitive dysfunction is the most serious.[16, 17] In a prospective cohort study of 188 patients, 16.0% of the patients had neurological complications after brain tumor surgery. Another prospective cohort study reported that 11.4% of patients showed early postoperative neurosurgical complications after craniotomy for the excision of brain tumor. However, the studies have focused on immediate neurological complications after brain tumor surgery.[9, 18] Yet other studies have reported that 5–6% of patients have long-term neurological sequelae after craniotomy for excision of brain tumor.[19, 20] In our study, 15.8% of patients had newly acquired disability after craniotomy for excision of brain tumors, which was higher than that reported in other studies.[19, 20] However, our study used a postoperative follow-up period of one year for all patients, resulting in more newly developed brain disabilities and postoperative sequelae being captured than in previous studies. Considering the importance of QOL among brain tumor survivors, the longer duration of follow-up after surgery is a valuable aspect of this study.
Male sex, reoperation, and longer LOS were associated with a higher incidence of deteriorating QOL in this study. Although the exact mechanism of how sex impacts the development of neurological outcomes is not known, a previous study also reported that male sex had a higher risk of postoperative complications after brain tumor surgery. A longer LOS means that the patient might have suffered from postoperative complications during hospitalization after the brain surgery. Similarly, another study reported that prolonged LOS was associated with a higher incidence of long-term complications in patients who underwent craniectomy for head injury. Reoperation within one year of undergoing a craniotomy for brain tumor excision suggests that there might be an early tumor recurrence that requires surgery. Therefore, patients who underwent reoperation were at a higher risk of their QOL deteriorating than other patients.
Curiously, neither decreased income nor loss of job was associated with 2-year all-cause or cancer mortality after craniotomy for the excision of brain tumors in this study. A previous study related that decreased income or loss of job was not associated with long-term mortality among survivors of extracorporeal membrane oxygenation in South Korea. This lack of association might be due to the characteristics of the Korean public insurance system. The South Korean government pays almost all medical expenses for any individual who is diagnosed with severe and rare diseases such as cancer and severe intractable. The government pays almost all treatment and examination charges for the disease category that malignant neoplasm of the brain (C71*) is included in; therefore, although a patient may be unemployed or have a lower income after the surgery, it would not affect their long-term mortality.
The results of our study showed that newly acquired disability was associated with higher long-term mortality. This is in keeping with a retrospective study that stated that long-term neurological problems, such as stroke and tumor recurrence, were associated with increased long-term mortality in patients with meningioma. Another retrospective study reported that postoperative complications were associated with increased long-term mortality in children with brain tumor. In addition to these findings, our analysis suggests that newly acquired disability, especially brain disability, among adult patients who underwent craniotomy for excision of brain tumor were in a higher risk population that needs special attention to prevent long-term mortality.
Our study has several limitations. First, we did not take into consideration the type of brain tumor, such as glioma and meningioma, since this information was not available from the NHIS database. Second, important variables, such as body mass index, operative time, and anesthetic technique, were not adjusted for in this study as this information, too, was not available from our database. Third, as the public insurance and social welfare systems in South Korea affected our results, our findings might not be generalizable to other countries. However, our findings suggest that with proper financial and social welfare support, newly acquired disability might be the only risk factor for increased mortality after brain tumor surgery. Finally, we did not consider the severity and stage of brain tumors, such those listed in the World Health Organization’s classification system.
In conclusion, at the 1-year follow-up, approximately half of the patients in this study experienced a lower QOL (unemployment, decreased income, and newly acquired disability) after craniotomy for excision of brain tumors. Among the three QOL factors we analyzed, newly acquired disability due to brain disability, was associated with increased 2-year all-cause and brain cancer mortality.