Is the survival of patients treated with ipilimumab affected by antibiotics? An analysis of 1585 patients from the French National hospital discharge summary database (PMSI)

Figures & data

Table 1. Patient population and baseline characteristics

Characteristics	Overall population (n = 1585)	No infection (n = 1468)	Infection (n = 117)	p-value
Age at C1 in years, mean (SD)	62.2 (14.6)	62.3 (14.6)	61.1 (13.9)	.39
Males, n (%)	876 (55.3%)	808 (55.0%)	68 (58.1%)	.58
Severe malnutrition at C1, n (%)	34 (2.15%)	28 (1.91%)	6 (5.13%)	.035
Brain metastases at C1 or before C1, n (%)	277 (17.5%)	244 (16.6%)	33 (28.2%)	.002
Chemonaive, n (%)	663 (41.8%)	620 (42.2%)	43 (36.8%)	.29
Total number of previous courses of chemotherapy, median [IQR]	2 [0;7]	2 [0;7]	2 [0;8]	.53
Number of courses of chemotherapy during the year before C1, median [IQR]	1 [0;5]	1 [0;5]	2 [0;6]	.39
Cumulative length of hospital stays before C1 ≥ 50 days^1, n (%)	530 (33.4%)	477 (33.4%)	53 (45.3%)	.006

C1: the start date of the first course of ipilimumab

SD: standard deviation

IQR: interquartile range

¹Number of patients who were hospitalized for a total of ≥50 days before C1, taking into account all possible stays in the period 2008–2014.

Figure 1. Overall survival according to the Kaplan-Meier method, main analysis (p-value from the Cox bivariate model)

Table 2. The Cox model

	Bivariate HR [95% CI] and p-value	Multivariate HR: full model [95% CI] and p-value	Multivariate HR: final model [95% CI] and p-value
Age at C1, in years (ref. = 18–39)
40–64	1.08 [0.80; 1.44] p = .63	1.06 [0.80; 1.43] p = .70
65–95	0.71 [0.53; 0.96] p = .03	0.76 [0.56; 1.03] p = .08
Male sex	1.11 [0.95; 1.31] p = .20
Infection group	1.88 [1.46; 2.43] p = 10^−6	1.66 [1.28; 2.15] p = 10^−4	1.68 [1.30; 2.18] p = 10^−5
Severe malnutrition	4.85 [3.27; 7.20] p = 10^−15	4.18 [2.81; 6.23] p = 10^−12	4.39 [2.96; 6.53] p = 10^−13
Brain metastases	2.00 [1.66; 2.40] p = 10^−13	1.79 [1.48; 2.16] p = 10^−9	1.89 [1.57; 2.27] p = 10^−11
Previous chemotherapy	1.20 [1.00; 1.43] p = .04	1.08 [0.90; 1.30] p = .41
Cumulative length of hospital stays before C1 ≥ 50 days	1.12 [0.95; 1.33] p = .17	1.02 [0.86; 1.21] p = .86

Table

CI	Confidence interval
C1	First ever course of ipilimumab
CCAM	French common classification of medical procedures
CDU	French common dispensing unit
HR	Hazard ratio
ICD-10	International Statistical Classification of Diseases and Related Health Problems, 10^th revision
ICI	Immune checkpoint inhibitor
INCA	French National Cancer Institute
IQR	Interquartile range
PMSI	French National Hospital Discharge Summary Database
SD	Standard deviation

Appendix 2. Kaplan-Meier overall survival in a sensitivity analysis

Appendix 3. Kaplan-Meier overall survival in a negative control analysis

Availability of data and material

Requests for access to the data can be submitted to the corresponding author.