Table 3.

Association Between Pneumonia and the Use of Individual Second-Generation Antipsychotic Drugs Within 30 D Before the Index Date Stratified by Single Drug Use, the Specified Drug Combined With Clozapine, the Specified Drug Combined With Nonclozapine Antipsychotic(s), and Noncurrent Use (Reference Group)

	Single Antipsychotic Drug		Combined With Clozapine		Combined With Nonclozapine Antipsychotics
	Adjusted Risk Ratioa	95% CI	Adjusted Risk Ratioa	95% CI	Adjusted Risk Ratioa	95% CI
Clozapine	2.01**	1.54 –2.61	—	—	4.78**	3.68–6.23
Olanzapine	0.73	0.51–1.06	22.40**	9.43–53.18	2.33**	1.71–3.18
Quetiapine	0.86	0.61–1.23	14.76**	6.44–33.84	1.87**	1.37–2.56
Zotepine	0.97	0.65–1.47	4.80**	2.17–10.64	1.57	1.09–2.27
Risperidone	0.65**	0.53–0.80	7.49**	4.47–12.56	2.41**	1.93–3.00
Amisulpride	0.51	0.27–0.98	21.44**	4.49–102.30	1.36	0.80–2.29

^aAdjusted for Charlson comorbidity index at the first admission, and the following variables within 180 d before the index date, including the number of psychiatric hospital admissions, physical illnesses, and concomitant medications (listed in table 1)

*P < .01, **P < .001.