Gastrointestinal symptoms in a Japanese population: A health diary study

Table 1 Demographic, socioeconomic and clinical characteristics of the participants

Variable	All participants (n = 3365)		Developed GI symptoms (n = 856)		No GI symptoms (n = 2509)
	n	%	n	%	n	%
Demograchics
Gender
Male	1573	45.7	328	38.3	1245	49.6
Female	1792	53.3	528	61.7	1264	50.4
Age (yr)
0-9	651	19.3	155	18.1	496	19.8
10-19	431	12.8	104	12.1	327	13.0
20-29	416	12.4	133	15.5	283	11.3
30-39	476	14.1	139	16.2	337	13.4
40-49	490	14.6	134	15.7	356	14.2
50-59	345	10.3	76	8.9	269	10.7
60-69	331	9.8	61	7.1	270	10.8
70-79	188	5.6	45	5.3	143	5.7
≥ 80	37	1.1	9	1.1	28	1.1
Socioeconomic characteristics
Annual household income
< 3 000 000 Japanese yen	424	12.6	112	13.1	312	12.4
3 000 000 to < 5 000 000	652	19.4	189	22.1	463	18.5
5 000 000 to < 7 000 000	522	15.5	127	14.8	395	15.7
7 000 000 to < 10 000 000	426	12.7	111	13.0	315	12.6
10 000 000 to < 12 000 000	167	5.0	42	4.9	125	5.0
≥ 12 000 000	82	2.4	16	1.9	66	2.6
N/A	1092	32.5	259	30.3	833	33.2
Employment status
Full-time employee/self-employed	1086	32.3	274	32.0	812	32.4
Part-time employee	374	11.1	100	11.7	274	10.9
Retiree	129	3.8	26	3.0	103	4.1
Jobless or unable to work	91	2.7	24	2.8	67	2.7
Homemaker	490	14.6	153	17.9	337	13.4
Student	89	2.6	18	2.1	71	2.8
N/A	1106	32.9	261	30.5	845	33.7
Educational attainment
Junior high school or lower	84	2.5	16	1.9	68	2.7
High school graduate	471	14.0	122	14.3	349	13.9
Vocational college	135	4.0	38	4.4	97	3.9
1-3 yr of college	156	4.6	50	5.8	106	4.2
College degree	336	10.0	85	9.9	251	10.0
Graduate school degree	23	0.7	8	0.9	15	0.6
N/A	2160	64.2	537	62.7	1623	64.7
Baseline clinical characteristics
Previous GI diseases
Yes	326	9.7	117	13.7	209	8.3
No	2956	87.8	722	84.3	2234	89.0
N/A	83	2.5	17	2.0	66	2.6
No. of comorbidities
None	2548	75.7	646	75.5	1902	75.8
One	578	17.2	157	18.3	421	16.8
Two or more	239	7.1	53	6.2	186	7.4
PCS8 score
≥ 50	1930	57.4	458	53.5	1472	58.7
< 50	1304	38.8	363	42.4	941	37.5
N/A	131	3.9	35	4.1	96	3.8
MCS8 score
≥ 50	1704	50.6	368	43.0	1336	53.2
< 50	1530	45.5	453	52.9	1077	42.9
N/A	131	3.9	35	4.1	96	3.8

N/A: indicates data not available; GI: gastrointestinal; PCS8: physical component of SF8; MCS8: mental component of SF8.

Table 2 Incidence and the number of episodes of gastrointestinal symptoms (n = 3365)

Symptom	Incidence per month		Episodes in a month
	n	(% of total)	mean	SD
Any gastrointestinal symtoms	856	(25.44)	0.656	1.794
Diffuse abdominal pain	401	(11.92)	0.214	0.799
Upper abdominal pain	179	(5.32)	0.114	0.801
Diarrhea	169	(5.02)	0.095	0.651
Nausea	148	(4.40)	0.067	0.393
Constipation	70	(2.08)	0.064	0.689
Dyspepsia	86	(2.56)	0.051	0.423
Vomiting	44	(1.31)	0.016	0.164
Abdominal fullness	34	(1.01)	0.015	0.187
Heartburn	18	(0.53)	0.010	0.173
Lower abdominal pain	16	(0.48)	0.009	0.158
Hematemesis	1	(0.03)	0.000	0.017

SD: standard deviation. There were no participants with hematochezia.

Table 3 Rate ratios based on multivariable adjusted poisson regression analyses

Variable symptom	Female gender	Older age	Previous GI disease	No. of comorbidity	Better PCS8	Better MCS8
Any gastrointestinal symtoms	1.412	0.994	1.894	1.055	0.738	0.645
	(< 0.01)	(< 0.01)	(< 0.01)	NS	(< 0.01)	(< 0.01)
Diffuse abdominal pain	1.455	0.980	1.385	0.886	0.545	0.548
	(< 0.01)	(< 0.01)	(< 0.01)	NS	(< 0.01)	(< 0.01)
Upper abdominal pain	1.485	1.016	2.504	0.855	0.975	0.426
	(< 0.01)	(< 0.01)	(< 0.01)	(< 0.05)	NS	(< 0.01)
Diarrhea	0.765	0.972	1.485	0.981	0.636	0.986
	(< 0.05)	(< 0.01)	(< 0.05)	NS	(< 0.01)	NS
Nausea	2.828	0.983	2.364	1.259	1.032	0.575
	(< 0.01)	(< 0.01)	(< 0.01)	(< 0.01)	NS	(< 0.01)
Dyspepsia	1.171	1.033	4.035	0.888	0.462	1.068
	NS	(< 0.01)	(< 0.01)	NS	(< 0.01)	NS
Constipation	2.877	1.014	1.198	1.427	1.234	0.364
	(< 0.01)	(< 0.01)	NS	(< 0.01)	NS	(< 0.01)
Vomiting	0.847	0.940	1.617	1.141	0.903	1.421
	NS	(< 0.01)	NS	NS	NS	NS
Abdominal fullness	1.833	1.020	1.871	0.936	1.305	0.476
	NS	(< 0.05)	NS	NS	NS	(< 0.05)
Heartburn	0.286	1.053	2.653	1.027	1.324	1.227
	(< 0.01)	(< 0.01)	(< 0.05)	NS	NS	NS
Lower abdominal pain	1.555	1.005	0.844	1.023	0.699	0.515
	NS	NS	NS	NS	NS	NS

GI: gastrointestinal; PCS8: physical component of SF8; MCS8: mental component of SF8. Adjusted for all covariates shown above. The numbers of parehtheses indicate statistically significant P-values. Age and No. of comorbidity were treated as continuous variables. PCS8 and MCS8 were treated as binary variables with cutoff pint of 50. Hematemesis and hematochezia could not be analyzed becaused of few incidence.

Table 4 Health care utilization in a month among the participants with gastrointestinal symptoms

Symptom	Visits to a physician		Dietary CAM uses		Physical CAM uses
	mean (d)	SD	mean (d)	SD	mean (d)	SD
Any gastrointestinal symptoms	0.67	1.502	1.82	5.614	0.12	0.891
Diffuse abdominal pain	0.58	1.518	1.48	5.075	0.10	1.133
Upper abdominal pain	0.45	1.040	2.76	6.823	0.32	1.791
Diarrhea	0.81	1.300	1.39	4.747	0.07	0.431
Nausea	0.76	1.274	1.70	4.738	0.25	1.851
Dyspepsia	0.50	1.344	4.47	8.023	0.52	2.533
Constipation	0.90	1.746	2.43	6.333	0.20	0.651
Vomiting	1.64	2.354	0.89	2.442	0.00	0.00
Abdominal fullness	0.32	0.638	2.91	6.440	0.06	0.343
Heartburn	0.44	0.784	2.11	3.692	0.50	1.465
Lower abdominal pain	0.63	1.628	2.06	7.206	0.19	0.750
Hematemesis	0.00	0.000	0.00	0.000	0.00	0.000

CAM: complementary and alternative medicine; SD: standard deviation. Hematochezia could not be analyzed becaused of few incidence.