On the Asymmetric Relationship Between Physician Mental Health Disorders on Quality of Healthcare Under the COVID-19 Pandemic in Taiwan: Quantile on Quantile Regression Analyses

Figures & data

Table 1 Descriptive Statistics and Unit Root Tests

Panel A: Descriptive Statistics
Variables	Description	Mean	Median	Max	Min	SD	Skew	Kurt	JB Stat	p value
Inpatient Care Quality (ICQt)	14-day readmission rate as measured by unplanned inpatient readmissions with-in 14 days per 100,000 discharge cases	28.746	31.964	44.510	0.987	7.984	−0.612	2.396	24.898	0.000
Outpatient Care Quality (OCQt)	Preventable hospitalization rate defined as preventable hospitalizations per 100,000 population based on the PQI90.	2.716	2.801	3.841	0.089	0.642	−0.769	3.539	35.545	0.000
Emergency Care Quality (ECQt)	The proportion of non-urgent visits to the emergency department in hospitals (%) based on the NYU algorithm.	23.309	23.167	29.425	19.959	1.741	0.901	3.831	52.678	0.000
Physician Mental Health (PMHt)	Ratio of physician mental health disorders prevalence to general population mental health disorders prevalence.	1.438	1.133	8.777	0.389	1.038	3.777	19.783	4530.487	0.000
Social Distance Index (SDIt)	A composite index based on the change of time spent in six different categories of places.	3.785	3.167	19.167	−7.000	4.079	0.654	4.023	36.848	0.000
SICQt	ICQt ÷ standard deviation of ICQt	3.600	4.003	5.575	0.124	1.000	−0.612	2.396	24.898	0.000
SOCQt	OCQt ÷ standard deviation of OCQt	4.232	4.366	5.987	0.139	1.000	−0.769	3.539	35.545	0.000
SECQt	ECQt ÷ standard deviation of ECQt	13.388	13.306	16.900	11.463	1.000	0.901	3.831	52.678	0.000
SPMHt	PMHt ÷ standard deviation of PMHt	1.385	1.091	8.453	0.374	1.000	3.777	19.783	4530.487	0.000
SSDIt	SSDIt ÷ standard deviation of SSDIt	0.928	0.776	4.699	−1.716	1.000	0.654	4.023	36.848	0.000
Panel B: Unit	Model Specification	Constant					Constant +Trend
Root Tests	Variables	T stat		p value			T stat		p value
	SICQt	−13.567		0.000			−13.817		0.000
Phillips-Perron	SOCQt	−10.402		0.000			−10.299		0.000
Unit Root Tests	SECQt	−10.352		0.000			−11.502		0.000
	SPMHt	−34.982		0.000			−33.661		0.000
	SSDIt	−11.987		0.000			−11.805		0.000

Notes: The sample period ran from February 15, 2020 to December 31, 2020, resulting in a total of 321 daily observations. Bold fonts denote 1% or more rigorous significance level. SD and Kurt mean Standard Deviation, and Kurtosis, respectively.

Table 2 Impact of Physician Mental Health on Healthcare Quality

Panel A: Inpatient Care Quality: 14-day readmission rate
		X0.10	X0.20	X0.30	X0.40	X0.50	X0.60	X0.70	X0.80	X0.90
Y0.10	Coef	−3.645	−3.643	−2.092	0.310	−1.537	−1.602	−1.257	−0.607	−0.470
	p value	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)
Y0.20	Coef	11.053	10.689	2.663	1.769	0.501	0.795	0.067	0.465	−0.013
	p value	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.14)	(0.99)
Y0.30	Coef	−2.660	−5.796	−0.113	1.571	1.196	0.687	−0.391	−0.230	−1.952
	p value	(0.36)	(0.00)	(0.88)	(0.00)	(0.00)	(0.00)	(0.17)	(0.89)	(0.83)
Y0.40	Coef	11.760	8.017	8.792	1.502	1.660	1.022	1.006	−0.098	−0.280
	p value	(0.40)	(0.02)	(0.00)	(0.00)	(0.00)	(0.00)	(0.03)	(0.56)	(0.36)
Y0.50	Coef	−6.086	−6.345	−4.655	−1.221	−1.023	−0.072	2.164	3.321	3.186
	p value	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.21)	(0.00)	(0.00)	(0.46)
Y0.60	Coef	2.922	2.200	−0.865	−0.034	−0.147	−0.211	−1.225	−1.594	−0.992
	p value	(0.00)	(0.00)	(0.16)	(0.37)	(0.00)	(0.00)	(0.88)	(0.00)	(0.15)
Y0.70	Coef	−6.569	−5.958	−4.472	−2.718	−0.509	−0.622	−0.695	−1.394	−0.412
	p value	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.21)	(0.02)	(0.77)
Y0.80	Coef	−0.502	−0.541	−1.102	−1.525	−2.709	−2.533	−2.716	−2.623	−2.266
	p value	(0.54)	(0.00)	(0.38)	(0.03)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)
Y0.90	Coef	0.058	0.035	0.008	0.013	0.012	0.037	0.018	−0.022	−0.105
	p value	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)
Panel B: Outpatient Care Quality: Preventable hospitalization Rate
		X0.10	X0.20	X0.30	X0.40	X0.50	X0.60	X0.70	X0.80	X0.90
Y0.10	Coef	−0.210	0.223	−1.407	−1.296	−1.418	−0.761	−2.760	−1.220	−2.306
	p value	(0.11)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.91)
Y0.20	Coef	0.552	1.065	2.562	3.116	3.210	2.654	1.990	−1.166	−1.652
	p value	(0.01)	(0.02)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.46)	(0.47)
Y0.30	Coef	−0.668	−0.998	−1.291	−1.286	−2.600	−3.080	−0.731	−1.145	−1.973
	p value	(0.46)	(0.06)	(0.02)	(0.00)	(0.00)	(0.00)	(0.00)	(0.05)	(0.82)
Y0.40	Coef	0.691	3.238	1.700	1.355	1.899	1.816	0.878	1.593	3.203
	p value	0.32	0.19	0.18	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	0.08
Y0.50	Coef	0.219	−0.323	0.944	3.743	5.063	5.847	3.774	1.913	3.770
	p value	(0.51)	(0.14)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.10)	(0.00)
Y0.60	Coef	−0.229	−0.935	−1.722	−3.624	−4.022	−2.978	−1.274	−0.778	−0.977
	p value	(0.62)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.93)
Y0.70	Coef	−1.719	−1.120	−1.531	−1.243	−1.258	−1.366	−0.936	0.848	0.517
	p value	(0.25)	(0.00)	(0.02)	(0.02)	(0.00)	(0.00)	(0.00)	(0.08)	(0.03)
Y0.80	Coef	0.228	0.110	0.187	−0.062	0.204	−0.461	−0.215	−0.408	−0.322
	p value	(0.15)	(0.41)	(0.97)	(0.77)	(0.00)	(0.00)	(0.00)	(0.00)	(0.41)
Y0.90	Coef	0.227	0.190	0.145	0.098	0.054	0.087	0.027	0.161	0.153
	p value	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)
Panel C: Emergence Care Quality: Proportion of Non-urgent ED Visits (%)
		X0.10	X0.20	X0.30	X0.40	X0.50	X0.60	X0.70	X0.80	X0.90
Y0.10	Coef	−1.531	−1.324	−1.079	−1.212	−2.143	−1.283	0.297	0.691	0.283
	p value	(0.63)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)
Y0.20	Coef	1.566	0.716	−0.200	0.383	−0.403	−0.772	−2.818	−4.498	−2.643
	p value	(0.19)	(0.05)	(0.47)	(0.00)	(0.00)	(0.00)	(0.01)	(0.16)	(0.30)
Y0.30	Coef	0.318	1.357	1.675	0.993	0.030	0.630	−0.218	0.958	1.239
	p value	(0.86)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.56)	(0.02)
Y0.40	Coef	−0.249	−1.022	0.629	1.595	1.263	1.150	2.148	0.401	−0.057
	p value	(0.94)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.02)	(0.84)	(0.99)
Y0.50	Coef	−0.403	0.300	−2.705	−3.814	−2.774	−2.505	−1.922	−0.423	1.920
	p value	(0.94)	(0.87)	(0.00)	(0.00)	(0.00)	(0.00)	(0.03)	(0.00)	(0.08)
Y0.60	Coef	−1.857	−0.052	−0.419	0.080	0.530	−0.299	0.491	−0.092	−0.303
	p value	(0.00)	(0.84)	(0.52)	(0.00)	(0.00)	(0.00)	(0.00)	(0.95)	(0.95)
Y0.70	Coef	0.659	1.119	0.914	0.832	1.953	1.624	1.148	1.326	1.223
	p value	(0.40)	(0.18)	(0.94)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.77)
Y0.80	Coef	1.113	1.399	1.473	1.578	1.617	1.527	2.138	2.531	1.763
	p value	(0.67)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)
Y0.90	Coef	0.235	0.207	0.189	0.214	0.151	0.132	0.098	0.043	0.198
	p value	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)

Notes: Bold fonts denote 10% or more rigorous significance levels. Red and blue fonts represent negative and positive impacts of PMH on healthcare quality, respectively.

Figure 1 Impact of each quantile of physician mental health disorders (PMH) on various quantiles of inpatient care quality of (ICQ).

Notes: Sub-figures (A–D) illustrate the effects of each quantile of PMH on the 0.1 (ICQ_0.1), 0.2 (ICQ_0.2), 0.3 (ICQ_0.3) quantile and the low quantiles of ICQ (ie, aggregate over low quantiles of ICQ), respectively; Sub-figures (E–H) illustrate the effects of each quantile of PMH on the 0.4 (ICQ_0.4), 0.5 (ICQ_0.5), 0.6 (ICQ_0.6) quantile and the middle quantiles of ICQ (ie, aggregate over middle quantiles of ICQ), respectively; Sub-figures (I–L) illustrate the effects of each quantile of PMH on the 0.7 (ICQ_0.7), 0.8 (ICQ_0.8), 0.9 (ICQ_0.9) quantile and the high quantiles of ICQ (ie, aggregate over high quantiles of ICQ), respectively; Sub-figure (M) depicts the cumulative impact of each PMH quantile across all quantiles of ICQ (ie, aggregate over all quantiles of ICQ).

Figure 2 Impact of each quantile of physician mental health disorders (PMH) on various quantiles of outpatient care quality (OCQ).

Notes: Sub-figures (A–D) illustrate the effects of each quantile of PMH on the 0.1 (OCQ_0.1), 0.2 (OCQ_0.2), 0.3 (OCQ_0.3) quantile and the low quantiles of OCQ (ie, aggregate over low quantiles of OCQ), respectively; Sub-figures (E–H) illustrate the effects of each quantile of PMH on the 0.4 (OCQ_0.4), 0.5 (OCQ_0.5), 0.6 (OCQ_0.6) quantile and the middle quantiles of OCQ (ie, aggregate over middle quantiles of OCQ), respectively; Sub-figures (I–L) illustrate the effects of each quantile of PMH on the 0.7 (OCQ_0.7), 0.8 (OCQ_0.8), 0.9 (OCQ_0.9) quantile and the high quantiles of OCQ (ie, aggregate over high quantiles of OCQ), respectively; Sub-figure (M) depicts the cumulative impact of each PMH quantile across all quantiles of OCQ (ie, aggregate over all quantiles of OCQ).

Figure 3 Impact of each quantile of physician mental health disorders (PMH) on various quantiles of emergency care quality (ECQ).

Notes: Sub-figures (A–D) illustrate the effects of each quantile of PMH on the 0.1 (ECQ_0.1), 0.2 (ECQ_0.2), 0.3 (ECQ_0.3) quantile and the low quantiles of ECQ (ie, aggregate over low quantiles of ECQ), respectively; Sub-figures (E–H) illustrate the effects of each quantile of PMH on the 0.4 (ECQ_0.4), 0.5 (ECQ_0.5), 0.6 (ECQ_0.6) quantile and the middle quantiles of ECQ (ie, aggregate over middle quantiles of ECQ), respectively; Sub-figures (I–L) illustrate the effects of each quantile of PMH on the 0.7 (ECQ_0.7), 0.8 (ECQ_0.8), 0.9 (ECQ_0.9) quantile and the high quantiles of ECQ (ie, aggregate over high quantiles of ECQ), respectively; Sub-figure (M) depicts the cumulative impact of each PMH quantile across all quantiles of ECQ (ie, aggregate over all quantiles of ECQ).