Characteristics of comorbidities and costs among patients who died from systemic lupus erythematosus in Taiwan Another interesting issue was that elderly patients (age ≥ 65 years) tended to be male and to have ALRC. A previous local epidemiological study reported a definitely better prognosis in young-mid- dle aged female SLE patients and a lower survival rate of male SLE patients in Taiwan [10]. The rea- sons for the discrepancy with previous reports are unknown. It is possible that male patients with SLE have been overlooked and underestimated in Tai- wan owing to a low index of suspicion by clinical practitioners other than rheumatologists because of overwhelming comorbidities, and by patients and their families. The higher ratio of ALRC implied that respiratory tract infections constitute a major problem in elderly SLE patients. Relevant studies were rare in aged SLE patients because their counts were limited. Further extensive cohort investiga- tions may be necessary to clarify this point. The understanding of the implications and path- ogenic relevance of comorbid cancers in SLE has changed in the past decade. Recent studies have demonstrated an increased incidence of cervical, bladder, lung and hematological cancers in SLE patients [33, 34]. Chen et al. have reported an over- all increased risk of cancers in Taiwanese SLE patients [35]. Our results demonstrated similar fea- tures in critical SLE patients, although the number of patients enrolled was much lower than in other investigations. The reason why these comorbid can- cers involve the hematological, respiratory and gen- itourinary systems is unknown. Further in-depth investigation is mandatory to determine whether long-term immunosuppressive medications or sim- ilar immunopathogenetic mechanisms with SLE caused comorbid cancers. On the other hand, the absence of a correlation between cancer incidence and some acute illnesses in dying SLE patients sug- gests that lethal infections may be more important factors in causing death than associated cancers. Similarly, the lack of association between cancers and chronic illness such as nephropathy/nephritis has indicated that renal inflammation may not be an essential factor for the development of malig- nancies in aged SLE patients. Further investigations may be necessary to clarify the issue. There were a few limitations in this study. Pos- sible errors in registration of the patients are unavoidable in a large population of patients like this. Absence of detailed relevant laboratory data, specific serum markers and records of immuno- suppressive prescriptions in claim data restricted the power of the study to evaluate the activity or severity of SLE itself. Absence of linkage with a mor- tality dataset also limited the in-depth approach to cause of death due to official and legal limitations. LN could not be discussed separately from nephropathy/nephritis owing to limitations of pres- ent ICD-9-CM coding. Nevertheless, the present investigation constitutes a novel approach to study the SLE patients on the verge of death on a nation- wide scale. Further case-controlled or cohort stud- ies are necessary for a more in-depth understand- ing of the natural course of SLE. In conclusion, a survey of the end-of-life hospi- talization of patients with SLE has identified the various characteristics of these patients during the end stage of the disease. Sepsis/bacteremia, acute respiratory failure, and ALRC were common acute co-morbidities in dying SLE patients. Nephropa- thy/nephritis mainly manifested in younger sub- ject. Elderly SLE patients presented with unique characteristics during the last period of survival, which require further assessment. The difficulties in the care of SLE inpatients challenge healthcare providers, who require more awareness to reduce disease per se or complications in dying SLE patients. Acknowledgments The authors wish to thank the National Health Research Institute for permission and authorization to utilize the dataset. The first author wrote this arti- cle in memory of his late mother, Madam Jing-Mei Chuang, who passed away with end-stage LN and iatrogenic infections. This study does not represent the official viewpoints of the National Health Research Institute, Taiwan. The work was support- ed in part by grants from the National Science Coun- cil Taiwan (NSC97-2314-B-075-009-MY3) and Taipei Veterans General Hospital (V99C1-129). The authors declare no conflict of interest about this study. R e f e r e n c e s 1. 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