Health-related quality of life in health states corresponding to different stages of perianal fistula associated with Crohn’s disease: a quantitative evaluation of patients and non-patients in Japan

Figures & data

Table 1. Descriptions of health states of perianal fistula associated with Crohn’s disease used in the survey.

#	Health state	Description
#1.	Remission	You have a condition that causes inflammation of the gastrointestinal tract. This inflammation can occur within your intestines, anywhere from near your mouth to your anus. People with this condition can experience stomach cramps and a need to go to the toilet urgently. Some people with this condition can experience fistulae, which are small holes, near the intestine and the anus. The opening of fistulae is a small hole at the skin, blood, mucus, pus or fece may leak out. It may accompany fever and pain. However, your condition is well controlled. You do not have pain associated with the fistulae and do not experience any discharge from around the anus. Your daily activities are not restricted and there are no physical restrictions on your sexual activity as a result of fistulae.
#2.	Chronic symptomatic fistulae with mild symptoms	You have a condition that causes inflammation of the gastrointestinal tract. This inflammation can occur within your intestines, anywhere from near your mouth to your anus. People with this condition can experience stomach cramps and a need to go to the toilet urgently. Some people with this condition can experience fistulae, which are small holes, near the intestine and the anus. The opening of fistulae is a small hole at the skin, blood, mucus, pus or fece may leak out. It may accompany fever and pain. These sometimes cause you mild discomfort and a small amount of mucus sometimes leaks from the fistulae opening. You have no or slight restrictions on your daily activities. You have slight restrictions on your sexual activity.
#3.	Chronic symptomatic fistulae with severe symptoms	You have a condition that causes inflammation of the gastrointestinal tract. This inflammation can occur within your intestines, anywhere from near your mouth to your anus. People with this condition can experience stomach cramps and a need to go to the toilet urgently. Some people with this condition can experience fistulae, which are small holes, near the intestine and the anus. The opening of fistulae is a small hole at the skin, blood, mucus, pus or fece may leak out. It may accompany fever and pain. These sometimes cause you moderate or marked discomfort. You experience moderate or substantial discharge from the fistulae openings, which contains mucus, pus and/or poo. Your daily activities are moderately to markedly restricted as a result of the fistulae. You have moderate or marked restrictions on your sexual activity as well.
#4.	Abscess	You have a condition that causes inflammation of the gastrointestinal tract. This inflammation can occur within your intestines, anywhere from near your mouth to your anus. People with this condition can experience stomach cramps and a need to go to the toilet urgently. Some people with this condition can experience fistulae, which are small holes, near the intestine and the anus. The opening of fistulae is a small hole at the skin, blood, mucus, pus or fece may leak out. It may accompany fever and pain. These fistulae are infected, and an abscess has developed. Pus accumulated is called as abscess. As abscess grows, severe pain may occur, and you may experience swelling around your anus. Your daily activities are moderately to severely restricted as a result of the infection. You have moderate to severe restrictions on your sexual activity as well.
#5.	Defunctioning with positive outcome	You have a condition that causes inflammation of the gastrointestinal tract. It has not been possible to control your symptoms with drugs, and you have had an operation. Before the operation you regularly experienced severe pain and an urgent need to go to the toilet. You also experienced a regular and substantial discharge of mucus, pus and/or poo from around your anus. The operation created stoma at cranial to the fistulae so that digestive waste and intestinal fluid do not stimulate the anus and fistulae. It also re-routed part of your intestine to an opening, or stoma, so that waste products may be emptied into an external bag attached to your abdomen. The operation was a success, but you still have mild discomfort from the fistulae. A small amount of mucus may sometimes leak from the fistulae but your daily activities are not restricted. You have slight restrictions on your sexual activity.
#6.	Defunctioning with negative outcome	You have a condition that causes inflammation of the gastrointestinal tract. It has not been possible to control your symptoms with drugs, and you have had an operation. Before the operation you regularly experienced severe pain and an urgent need to go to the toilet. You also experienced a regular and substantial discharge of mucus, pus and/or poo from around your anus. The operation created stoma at cranial to the fistulae so that digestive waste and intestinal fluid do not stimulate the anus and fistulae. It also re-routed part of your intestine to an opening, or stoma, so that waste products may be emptied into an external bag attached to your abdomen. The operation has not completely relieved your symptoms and you still regularly experience moderate to severe pain. You also experience a regular and substantial discharge of mucus, pus and/or poo from the fistulae openings. Your daily activities are severely restricted as a result of the fistulae. You have moderate to severe restrictions on your sexual activity as well.
#7.	Proctectomy with positive outcome	You have a condition that causes inflammation of the gastrointestinal tract. It has not been possible to control your symptoms with drugs, and you have had an operation. Before the operation you regularly experienced severe pain and an urgent need to go to the toilet. You also experienced a regular and substantial discharge of mucus, pus and/or poo from around your anus. The operation removed your back passage (rectum) including fistulae and an abscess to create stoma. It also re-routed part of your intestine to an opening, or stoma, so that waste products may be emptied into an external bag attached to your abdomen. It is not possible to reverse the operation and you will always require the stoma and external bag. The operation was a success and you do not have any pain or discharge from around the anus. Your daily activities are not restricted. You have slight restrictions on your sexual activity.
#8.	Proctectomy with negative outcome	You have a condition that causes inflammation of the gastrointestinal tract. It has not been possible to control your symptoms with drugs, and you have had an operation. Before the operation you regularly experienced severe pain and an urgent need to go to the toilet. You also experienced a regular and substantial discharge of mucus, pus and/or poo from around your anus. The operation removed your back passage (rectum) including fistulae and an abscess to create stoma. It also re-routed part of your intestine to an opening, or stoma, so that waste products may be emptied into an external bag attached to your abdomen. It is not possible to reverse the operation and you will always require the external bag. The operation has not completely relieved your symptoms and you still regularly experience moderate to severe pain. You also experience discharge from the surgery wound which has not fully healed. Your daily activities are severely restricted as a result of the surgery wound. You have moderate to severe restrictions on your sexual activity as well.

Figure 1. Example of standard time trade-off internet survey screen.

Note: TTO, time trade-off

Figure 2. Example of lead-time time trade-off internet survey screen.

Note: TTO, time trade-off

Figure 3. Flow chart of participants.* Total number of Medilead Healthcare Panel registrants. When registering for the panel, a total of 419 people reported that they had visited a medical institution for Crohn’s disease in the past. ** Comprises 419 people registered as having visited a medical institution for Crohn’s disease and 13,190 people randomly selected from the remaining non-Crohn’s disease patients. *** The allocation to the patient or non-patient group was based on the results of the screening survey, not on the information given by people when they registered with the panel. QOL, quality of life; TTO, time trade-off

Table 2. Background information of valid responders.

	Patient group	Non-patient group
	(n = 82)	(n = 576)
Sex (%)
Male	70.7	44.1
Female	29.3	55.9
Age (%)
20–29 years old	3.7	12.0
30–39 years old	15.9	12.5
40–49 years old	37.8	17.4
50–59 years old	31.7	15.1
60–69 years old	11.0	15.6
70 years or older	0.0	27.4
Current health state (%)
Very poor	2.4	1.4
Poor	12.2	5.9
Fair	58.5	45.3
Good	24.4	38.5
Very good	2.4	8.9
Presence of own disability (%)
Yes	45.1	7.6
No	51.2	89.6
Do not want to answer	3.7	2.8
Family/friend with Crohn’s disease (%)
Yes	NA*	1.9
Chronic perianal fistula (%)
Currently experiencing	7.3	NA*
Previously experienced but not experiencing now	41.5	NA*
Never experienced	51.2	NA*
Perianal abscess (%)
Currently experiencing	9.8	NA*
Previously experienced but not experiencing now	46.3	NA*
Never experienced	43.9	NA*
Proctostomy (%)
Yes	19.5	NA*

Note: * No response data because this question was not asked in this group.

NA, not applicable.

Table 3. Utility values in each health state.

		Patient group (n = 82)		Non-patient group (n = 576)
Health state		Mean	± SD	Mean	± SD
#1.	Remission	0.78	±0.33	0.51	±0.51
#2.	Chronic symptomatic fistulae with mild symptoms	0.60	±0.48	0.30	±0.59
#3.	Chronic symptomatic fistulae with severe symptoms	0.23	±0.63	−0.04	±0.63
#4.	Abscess	0.21	±0.60	−0.08	±0.62
#5.	Defunctioning with positive outcome	0.50	±0.59	0.33	±0.58
#6.	Defunctioning with negative outcome	0.13	±0.68	−0.09	±0.64
#7.	Proctectomy with positive outcome	0.53	±0.55	0.37	±0.59
#8.	Proctectomy with negative outcome	0.13	±0.65	−0.10	±0.64

Note: SD, standard deviation.

Table 4. Utility values based on actual health state at the time of the survey of patients with Crohn’s disease.

	n	Mean	± SD
Patient group, overall	82	0.71	±0.48
Chronic perianal fistula
Currently experiencing	6	0.63	±0.80
Previously experienced but not experiencing now	34	0.64	±0.53
Never experienced	42	0.77	±0.38
Perianal abscess
Currently experiencing	8	0.67	±0.68
Previously experienced but not experiencing now	38	0.70	±0.46
Never experienced	36	0.73	±0.47
Proctostomy
Yes	16	0.71	±0.49
No	66	0.71	±0.48

Note: SD, standard deviation.

Table 5. Results of linear mixed model analysis of utility values.

Explanatory variables		Partial regression coefficient	Standard error	P-value
Responder category	Patient group (ref.)
	Non-patient group	−0.278	0.064	<0.001***
Health state descriptions	#1. Remission (ref.)
	#2. Chronic symptomatic fistulae with mild symptoms	−0.213	0.022	<0.001***
	#3. Chronic symptomatic fistulae with severe symptoms	−0.552	0.022	<0.001***
	#4. Abscess	−0.596	0.022	<0.001***
	#5. Defunctioning with positive outcome	−0.192	0.022	<0.001***
	#6. Defunctioning with negative outcome	−0.610	0.022	<0.001***
	#7. Proctectomy with positive outcome	−0.153	0.022	<0.001***
	#8. Proctectomy with negative outcome	−0.615	0.022	<0.001***
Sex	Male (ref.)
	Female	−0.017	0.038	0.655
Age	20–29 years old (ref.)
	30–39 years old	0.014	0.077	0.857
	40–49 years old	0.004	0.071	0.955
	50–59 years old	0.105	0.073	0.151
	60–69 years old	0.080	0.075	0.284
	70 years or older	0.132	0.069	0.055
Current health state	Very poor (ref.)
	Poor	−0.159	0.167	0.341
	Fair	−0.109	0.156	0.482
	Good	−0.111	0.158	0.482
	Very good	−0.101	0.169	0.550
Presence of own disability	Yes (ref.)
	No	0.056	0.065	0.389
	Do not want to answer	−0.057	0.123	0.645
(Constant)		0.800	0.171	<0.001***

Note: Explanatory variables: dummy variables (0–1)

Objective variables: Utility values (−1.00–1.00). * P < 0.05, ** P < 0.01, *** P < 0.001

Marginal R², 0.154; conditional R², 0.640.

Data availability statement

We have not acquired an agreement from participants of this study for data to be shared publicly, so supporting data are not available.