Table 1.

Studied population in relation to the general population of Poland, by age group, sex and urbanization degree, July 2009–April 2011

Characteristic	Population of Poland (N = 36 954 352 inhabitants >3 years)		Observed study population (N = 197 955 person-years)		Patients with cough (N = 3864)
	Inhabitants	%	Person-years	%	n	%	GP visits/100 person-years
Age (years)
3–5	1 121 700	3·04	9310	4·71	366	9·48	393·1
6–9	1 414 229	3·83	10 744	5·43	378	9·79	351·8
10–14	1 976 891	5·35	13 522	6·84	276	7·15	204·1
15–19	2 418 066	6·54	15 626	7·90	307	7·95	196·5
20–24	2 850 276	7·71	14 158	7·16	189	4·89	133·5
25–29	3 290 233	8·90	14 536	7·35	198	5·13	136·2
30–34	3 081 213	8·34	13 807	6·98	218	5·64	157·9
35–39	2 727 569	7·38	12 591	6·37	230	5·96	182·7
40–44	2 348 393	6·35	11 320	5·72	190	4·92	167·8
45–49	2 443 818	6·61	12 554	6·35	228	5·90	181·6
50–54	2 914 321	7·89	13 985	7·07	318	8·23	227·4
55–59	2 856 502	7·73	13 889	7·02	285	7·38	205·2
60–64	2 326 577	6·30	14 154	7·16	257	6·65	181·6
65–69	1 355 471	3·67	11 139	5·63	162	4·19	145·4
>70	3 829 093	10·36	16 620	8·40	262	6·78	157·6
Sex
Male	17 802 290	48·17	94 667	47·86	1654	42·83	17·5
Female	19 152 062	51·83	103 288	52·22	2210	57·22	21·4
Region
Central	7 520 646	20·35	20 372	10·30	483	12·51	23·7
Southern	7 691 095	20·81	29 720	15·03	757	19·60	25·5
Eastern	6 502 110	17·59	26 467	13·38	227	5·88	8·6
North-Western	5 913 681	16·00	34 311	17·35	637	16·49	18·6
South-Western	3 789 180	10·25	43 224	21·85	531	13·75	12·3
Northern	5 537 640	14·99	43 861	22·17	1229	31·82	28·0
Urbanization (township size)
<20 000	19 206 928	51·97	107 237	54·21	1430	37·03	13·3
20 000–100 000	7 164 520	19·39	26 066	13·18	348	9·01	13·4
>100 000	10 582 904	28·64	64 652	32·69	2086	54·01	32·3