Investigating the utilization of radiological services by physician patients: a population-based cohort study in Taiwan

Table 4 Utilization of radiology modalities per 1,000 person-years stratified by major diseases

Modality	No major diseases					Major diseases
	Physicians	General adults	Rate ratio	95% CI	Pvalue	Physicians	General adults	Rate ratio	95% CI	Pvalue
	n = 1,636	n = 1,640	Rate ratio	95% CI	Pvalue	n = 50	n = 46	Rate ratio	95% CI	Pvalue
X-ray	359	549	0.65	0.63–0.67	<0.001	1042	1330	0.78	0.70–0.87	<0.001
Sonography	138	148	0.93	0.88–0.98	0.009	432	435	0.99	0.83–1.19	0.94
Computed tomography	21	17	1.23	1.06–1.43	0.004	178	169	1.06	0.79–1.41	0.69
Magnetic resonance imaging	29	14	2.07	1.65–2.60	<0.001	124	39	3.17	1.47–7.57	0.001
Radioisotope scanning	9	7	1.30	0.91–1.87	0.14	56	126	0.44	0.22–0.87	0.01
Positron emission tomography	0.12	0	NA	NA	NA	28	17	1.65	0.41–7.50	0.47
Interventional procedures	11	16	0.69	0.58–0.82	<0.001	37	60	0.61	0.34–1.08	0.08

NA: not analyzed because no patients in the control received positron emission tomography; 95% CI: 95% confidence interval.

ISSN: 1472-6963