Table 4.

Direct, indirect and total effects of the factors on THC in elderly patients (≥65 y old) using a structure equation model

Variable	Direct effect (USDa)			Indirect effect (USDa)			Total effects (USDa)
	→THC			→LOS→THC			→THC + (→LOS→THC)
	Coeff.	95% CI		Coeff.	95% CI		Coeff.	95% CI
LOS (day)	293	279	307				293	279	307
Gender (reference: male)
Female	−201	−385	−17	471	238	703	269	−28	567
Hospitalization characteristics
Influenza as primary medical diagnosis	−526	−690	−361	−1920	−2160	−1680	−2446	−2716	−2176
Nature of hospitalization
Regular	Reference			Reference			Reference
Emergency	443	283	603	−265	−556	673	177	−109	464
ICU	4943	3966	5920	58	−556	673	5002	3732	6272
Patient origin
From home	Reference			Reference			Reference
Transfer	−332	−929	265	815	−179	1810	482	−515	1481
Nursing home or welfare facilities	−662	−875	−448	124	−221	470	−537	−922	−152
Associated conditions
Congestive heart failure	−216	−514	81	156	−171	484	−60	−493	373
Atrial fibrillation	−198	−589	192	48	−368	465	−150	−687	387
Acute respiratory failure	−33	−289	222	−345	−712	22	−379	−799	41
Acute renal failure	1093	−958	3145	−715	−1679	248	377	−1967	2723
Pneumonia	−406	−645	−168	−41	−358	274	−448	−824	−72
Asthma	−48	−518	422	26	−423	475	−21	−699	656
COPD	−316	−601	−30	287	−159	733	−28	−542	484
Chronic renal failure	−1009	−1516	−502	58	−595	713	−950	−1693	−207
Diabetes mellitus	182	−82	448	73	−207	355	256	−132	645
Disease involving the immune mechanism	5115	−3837	14 067	−874	−3519	1770	4240	−7000	15 481
Parkinson's disease	11	−386	409	1574	643	2505	1586	585	2586
Ischaemic heart disease	271	−132	675	336	−53	726	608	82	1134
Malignant neoplasm (cancer)	259	−83	603	723	333	1112	982	453	1512
Procedures (patients with at least 1 procedure charged)
Surgery and interventions
Blood transfusion	3354	2608	4099	2583	1936	3231	5938	4882	6993
Cardiac catheterization	70	−196	338	1516	1171	1862	1587	1167	2008
Dialysis	2123	1232	3014	659	−524	1842	2782	1288	4276
Mechanical ventilation	2519	1590	3448	−630	−1316	55	1888	741	3035
Oxygen therapy	241	−53	536	150	−204	505	392	−86	870
Tube feeding	1014	366	1662	2563	1956	3169	3578	2691	4464
Tests/imaging
Biochemical testing	114	−357	586	−460	−1313	392	−345	−1318	627
Bronchoscopy/pulmonary function test	2222	1123	3322	1636	766	2506	3859	2407	5311
Chest X‐ray	248	−124	621	733	249	1218	982	374	1590
Colour Doppler ultrasound/echocardiography	553	338	768	753	455	1051	1306	947	1665
Computerized tomography	−20	−213	172	533	292	774	513	204	821
Immunology test	37	−324	399	1166	711	1620	1203	619	1788
Oxygen saturation test	−51	−334	231	258	−83	600	207	−246	660
Sputum test	−212	−431	6	474	241	708	262	−58	582

Statistical significance at P‐value < 0.05 in bold. Coeff., unstandardized coefficient; USD, US$; LOS, length of stay; THC, total healthcare cost; COPD, chronic obstructive pulmonary disease.

^aExchange rate: 1 USD = 109.33 Japanese yen.