Socio-economic status and lifestyle factors are associated with achalasia risk: A population-based case-control study

Table 1 Descriptive characteristics of achalasia cases and matched controls n (%)

Characteristics	Achalasia cases	Controls
	n = 151	n = 117	P value
Age, yr (mean ± SD)	55.9 ± 17.1	55.8 (16.0)	0.97
Age at diagnosis (mean ± SD)	47.6 ± 17.8	/	/
Sex
Male	76 (50.3)	55 (47.0)
Female	75 (49.7)	62 (53.0)	0.59
Previous medical history
Ischaemic heart disease	12 (8.0)	7 (6.0)	0.53
Diabetes Mellitus	4 (2.7)	3 (2.6)	0.97
Hypertension	27 (17.9)	17 (14.5)	0.46
Hypercholesterolaemia	16 (10.6)	12 (10.3)	0.93
Asthma/COPD	11 (7.3)	4 (3.4)	0.17
Gastritis/Peptic ulcer	19 (12.6)	8 (6.8)	0.12
Autoimmune/Connective Tissue Disorders	1 (0.7)	1 (0.9)	0.86
Family history of achalasia	5 (3.3)	0 (0.0)	0.05
Number of years in education (mean, SD)	12.5 (3.3)	12.8 (3.1)	0.34
Occupation class
High	39 (25.8)	45 (38.5)
Medium	47 (31.1)	32 (27.4)
Low	55 (36.4)	34 (29.1)
Not classified	10 (6.6)	6 (5.1)	0.17

COPD: Chronic obstructive pulmonary disorder.

Table 2 Early life and childhood household factors and achalasia risk n (%)

Early life risk factors	Achalasia cases	Controls	Unadjusted	Adjusted2
	n = 151	n = 117	OR (95%CI)	OR (95%CI)
Number of rooms
< 6	71 (47.0)	54 (46.2)	1	1
≥ 6	80 (53.0)	63 (53.8)	0.97 (0.60-1.57)	0.96 (0.59-1.57)
Number of bedrooms
< 3	35 (23.2)	29 (24.8)	1	1
≥ 3	116 (76.8)	88 (75.2)	1.09 (0.62-1.92)	1.09 (0.61-1.96)
Household density
< 2	55 (36.4)	44 (37.6)	1	1
≥ 2	96 (63.6)	73 (62.4)	1.05 (0.64-1.73)	1.05 (0.64-1.73)
Toilet location
Indoors	85 (56.3)	73 (62.9)	1	1
Outdoor	66 (43.7)	43 (37.1)	1.32 (0.80-2.16)	1.55 (0.85-2.82)
Presence of smokers
No	38 (25.2)	26 (22.2)	1	1
Yes	113 (74.8)	91 (77.8)	0.85 (0.48-1.50)	0.85 (0.48-1.52)
Presence of any pets in the house1
No	36 (23.8)	31 (26.5)	1	1
Yes	115 (76.2)	86 (73.5)	1.15 (0.66-2.31)	1.17 (0.67-2.04)
Occupation of head of household
High	15 (9.9)	18 (15.4)	1	1
Medium	56 (37.1)	40 (34.2)	1.68 (0.76-3.73)	1.70 (0.77-3.79)
Low	78 (51.7)	57 (48.7)	1.64 (0.76-3.53)	1.69 (0.78-3.67)
Unclassified	2 (1.3)	2 (1.7)	1.20 (0.15-9.57)	1.25 (0.15-10.23)
Breastfed
No	63 (41.7)	48 (41.0)	1	1
Yes	61 (40.4)	51 (43.6)	0.91 (0.54-1.55)	0.89 (0.49-1.59)
Unknown	27 (17.9)	18 (15.4)	1.14 (0.56-2.31)	1.12 (0.54-2.31)

¹Compared with no pets present in the childhood house;

²Adjusted logistic regression model includes age (at interview) and sex.

Table 3 Early life and childhood household factors and achalasia risk n (%)

Risk factors	Achalasia cases	Controls	Unadjusted OR (95%CI)	Adjusted OR1
	n = 151	n = 117		(95%CI)
Occupation class
High	39 (25.8)	45 (38.5)	1	1
Medium	47 (31.1)	32 (27.4)	1.69 (0.91-3.15)	1.75 (0.93-3.29)
Low	55 (36.4)	34 (29.1)	1.87 (1.02-3.42)	1.88 (1.02-3.45)
Unclassified	10 (6.6)	6 (5.1)	1.92 (0.64-5.77)	1.90 (0.59-6.14)
Years in education
< 13 yr	91 (60.3)	64 (54.7)	1	1
≥ 13 yr	60 (39.7)	53 (45.3)	0.80 (0.49-1.30)	0.92 (0.52-1.61)
Smoking status
Non-smoker	91 (60.3)	61 (52.1)	1	1
Former smoker	36 (23.8)	28 (23.9)	0.86 (0.48-1.56)	0.82 (0.44-1.54)
Current smoker	24 (15.9)	28 (23.9)	0.57 (0.30-1.08)	0.47 (0.24-0.92)
Alcohol consumer
No	58 (38.4)	31 (26.5)	1	1
Yes	93 (61.6)	86 (73.5)	0.58 (0.34-0.98)	0.55 (0.32-0.95)
Combined alcohol/smoking status
Non-drinker and Non-smoker	46 (30.5)	20 (17.1)	1	1
Drinks alcohol or ever smoker	57 (37.8)	52 (44.4)	0.48 (0.25-0.91)	0.48 (0.25-0.93)
Drinks alcohol and ever smoker	48 (31.8)	45 (38.5)	0.46 (0.24-0.90)	0.41 (0.21-0.83)
History of foreign travel outside Europe
No	96 (63.6)	58 (49.6)	1	1
Yes	55 (36.4)	59 (50.4)	0.56 (0.34-0.92)	0.59 (0.35-0.99)
Presence of any pets in the house
No	37 (24.5)	44 (37.6)	1	1
Yes	114 (75.5)	73 (62.4)	1.86 (1.10-3.14)	1.92 (1.12-3.31)

¹Adjusted logistic regression model includes age (at interview), sex and socioeconomic status.