Ical Modification [ICD-9CM] codes including oropharyngeal cancer [146], hypopharyngeal cancer [148], and laryngeal cancer [161]) who were over 20 years of age and underwent radiotherapy, chemotherapy, or chemo-radiotherapy, with or without surgery, in 2010. A sample of 1083 patients was used based on the registry of catastrophic illness patient database and clinical exclusion criteria.MeasurementsA total of 1083 patients who met the MK8931 inclusion and exclusion criteria were identified. Each patient was tracked from his or her index ambulatory visit in 2010 to identify outcomes including any type of infectious diseases. To maximize case ascertainment, only patients hospitalized for infection events were included. These patients were then linked to the administrative data to calculate the rate of infection events. We compared the outcomes for patients who underwent MedChemExpress AN 3199 cetuximab therapy (the cetuximab group): chemotherapy (cisplatin/carboplatin-based), chemoradiotherapy, and surgery with chemoradiotherapy, and for those who did not receive cetuximab therapy (the non-cetuximab group): chemotherapy (cisplatin/ carboplatin -based), chemoradiotherapy, and surgery with chemoradiotherapy. The two major groups (cetuximab versus noncetuximab) were analyzed to explore the possible differences between cetuximab administration and infection events. Patients were characterized by age, gender, treatment modality, comorbidities, individual socioeconomic status, and tumor site. In each patient, the comorbidities were based on 23388095 the modified Charlson comorbidity index score, which was widely used in recent years for risk adjustment in administrative claims data sets [14]. The insurance amount from the database was used as a proxy for the individual socioeconomic status. The monthly income was classified into one of three categories: 1) low SES (lessResultsIn 1083 head and neck cancer patients, the median duration of follow-up was 6.5 months (interquartile range, 3.7? months). The mean age of the entire cohort was 57 years (standard deviation, 11 years). Among the participants, 96 were men and all patients were Asian. Among the patients with head and neck cancer, 158 were treated with cetuximab. Patients treated with cetuximab were older, and were more likely to have a lower socioeconomic statusInfection Risk in HNC with Cetuximab TherapyFigure 2. Distribution of explanatory variables between patients receiving cetuximab and those not receiving cetuximab for propensity score quintiles ranging from 1 (least likely to receive cetuximab) to 5 (most likely to receive cetxuimab). doi:10.1371/journal.pone.0050163.gand to live in 24786787 rural area, as compared to those who did not receive cetuximab therapy (Table 1). At the end of the follow-up period, 125 patients had infection events, and of these, 32 (20.3 ) were in the group using cetuximab and 93 (10.1 ) were in the group that did not use it (Figure 1). HNC patients with cetuximab therapy aged 55?4 years incurred the highest infection rate of 33 .Table 2 shows the types of infection events for the two groups. Pneumonia was the most common infectious disease complication in both groups. In subgroup analysis, there was no statistical difference between the infection rate and treatment modality (surgery with adjuvant therapy versus chemotherapy or chemoradiotherpy) in cetuximab group or without cetuximab group (P = 0.581 and 0.261, respectively) (Table 3). Patients using cetuximab had an increased risk of infection events (P,.Ical Modification [ICD-9CM] codes including oropharyngeal cancer [146], hypopharyngeal cancer [148], and laryngeal cancer [161]) who were over 20 years of age and underwent radiotherapy, chemotherapy, or chemo-radiotherapy, with or without surgery, in 2010. A sample of 1083 patients was used based on the registry of catastrophic illness patient database and clinical exclusion criteria.MeasurementsA total of 1083 patients who met the inclusion and exclusion criteria were identified. Each patient was tracked from his or her index ambulatory visit in 2010 to identify outcomes including any type of infectious diseases. To maximize case ascertainment, only patients hospitalized for infection events were included. These patients were then linked to the administrative data to calculate the rate of infection events. We compared the outcomes for patients who underwent cetuximab therapy (the cetuximab group): chemotherapy (cisplatin/carboplatin-based), chemoradiotherapy, and surgery with chemoradiotherapy, and for those who did not receive cetuximab therapy (the non-cetuximab group): chemotherapy (cisplatin/ carboplatin -based), chemoradiotherapy, and surgery with chemoradiotherapy. The two major groups (cetuximab versus noncetuximab) were analyzed to explore the possible differences between cetuximab administration and infection events. Patients were characterized by age, gender, treatment modality, comorbidities, individual socioeconomic status, and tumor site. In each patient, the comorbidities were based on 23388095 the modified Charlson comorbidity index score, which was widely used in recent years for risk adjustment in administrative claims data sets [14]. The insurance amount from the database was used as a proxy for the individual socioeconomic status. The monthly income was classified into one of three categories: 1) low SES (lessResultsIn 1083 head and neck cancer patients, the median duration of follow-up was 6.5 months (interquartile range, 3.7? months). The mean age of the entire cohort was 57 years (standard deviation, 11 years). Among the participants, 96 were men and all patients were Asian. Among the patients with head and neck cancer, 158 were treated with cetuximab. Patients treated with cetuximab were older, and were more likely to have a lower socioeconomic statusInfection Risk in HNC with Cetuximab TherapyFigure 2. Distribution of explanatory variables between patients receiving cetuximab and those not receiving cetuximab for propensity score quintiles ranging from 1 (least likely to receive cetuximab) to 5 (most likely to receive cetxuimab). doi:10.1371/journal.pone.0050163.gand to live in 24786787 rural area, as compared to those who did not receive cetuximab therapy (Table 1). At the end of the follow-up period, 125 patients had infection events, and of these, 32 (20.3 ) were in the group using cetuximab and 93 (10.1 ) were in the group that did not use it (Figure 1). HNC patients with cetuximab therapy aged 55?4 years incurred the highest infection rate of 33 .Table 2 shows the types of infection events for the two groups. Pneumonia was the most common infectious disease complication in both groups. In subgroup analysis, there was no statistical difference between the infection rate and treatment modality (surgery with adjuvant therapy versus chemotherapy or chemoradiotherpy) in cetuximab group or without cetuximab group (P = 0.581 and 0.261, respectively) (Table 3). Patients using cetuximab had an increased risk of infection events (P,.
