Why is misdiagnosis more likely among some people with rare diseases than others? Insights from a population-based cross-sectional study in China

Table 1 The characteristics of study sample

	Overall		Adult		Non-adult
	N	%	N	%	N	%
Sex
Male	1093	53.6	492	45.2	581	63.3
Female	947	46.4	597	54.8	337	36.7
Education
No education			47	4.3	34^*	6.7
Primary and secondary			312	28.7	172^*	33.8
Senior			248	22.8	175^*	34.4
College and above			482	44.3	128^*	25.1
Disease rarity level^a
Mildly rare	396	19.9	86	7.8	38	4.3
Moderately rare	1466	73.8	828	75.3	638	72.0
Extremely rare	124	6.2	186	16.9	210	23.7
Hukou^b
Urban	1061	52.2	609	56.1	432	47.3
Rural	970	47.8	477	43.9	481	52.7
Economic developed area^c
Develop area	898	44.0	483	44.4	402	43.8
Underdeveloped area	1142	56.0	606	55.6	516	56.2
Have been misdiagnosed
Yes	1310	66.1	755	72.2	534	59.1
No	671	33.9	290	27.8	370	40.9
Insurance^d
Free medical care			42	4.7
Urban employee Medical insurance			359	40.4
Urban resident medical insurance			130	14.6
New rural cooperative medical care			357	40.2
Difficult level to access information
A little difficult	462	23.3	269	25.6	187	20.7
Some difficult	769	38.7	416	39.7	337	37.2
Very difficult	755	38.0	364	34.7	381	42.1
Have complication
Yes	773	70.0	433	69.3	340	70.8
No	332	30.0	192	30.7	140	29.2
Perceived economical level as compared to locals^e
Below average	1342	66.9	698	64.1	644	70.2
Close to average	597	29.7	353	32.4	244	26.6
Above average	68	3.4	38	3.5	30	3.3

	Mean	SD	Mean	SD	Mean	SD
Age	22.46	17.13	36.08	10.77	6.37	4.68
Length of time to be diagnosed^f	2.26	4.81	3.46	6.08	0.83	1.91
Family size^g	2.73	1.14	3.27	0.87	2.08	1.08

^*The patient’s fraternal educational level
^aThe classification of rare disease was listed in the Additional file 1: Appendix
^bHukou is a system of household registration in mainland China. A household registration record officially identifies a person as a resident of an area. Currently there are two categories of Hukou system: urban registration and rural registration
^cThe developed areas included Beijing, Tianjin, Hebei, Shandong, Shanghai, Jiangsu, Zhejiang, Fujian, Guangdong, Hainan, Hong Kong SAR and Macau SAR
The underdeveloped areas included Chonqing, Sichuan, Hubei, Hunan, Anhui, Jiangxi, Shaanxi, Gansu, Ningxia, Shanxi, Yunnan, Guizhou, Guangxi, Jilin, Liaoning, Heilongjiang, Inner Mongolia, Tibet, Xinjiang and Qinghai
^dFree medical care only provides to civil servants
^ePerceived economic level is determined by the respondent’s self-assessment of their monthly family income. It is measured by a likert scale from 1–5. If the respondents think his/her family income is about the same as average level in the places where they live, they will choose 3; whereas 1–2 means lower than average local income level, and 4–5 means higher than average level
^fLength of time from symptom onset to an accurate diagnosis (years)
^gNumber of many family members living under the same roof

ISSN: 1750-1172