Introduction

In Poland, the leading cause of mortality are cardiovascular diseases (CVDs), which accounted for 36% of all deaths in 2022.1 In 2021, the age-standardized mortality rate from this cause was 359 per 100 000 population. Among men under the age of 45 years, it was nearly 3.5 times higher than in women of the same age. Among individuals over 60 years old, mortality due to CVDs is only slightly higher in men than in women.2 Furthermore, CVDs account for the highest percentage of healthy life-years lost.3 At the same time, hypertension remains the most important modifiable CV risk factor. It is one of the most prevalent diseases and the leading global cause of premature death.4,5 About 5% of hypertensive patients have resistant hypertension, and in 8% multiple drug intolerance syndrome occurs, more often in the female population.6,7 The number of patients with hypertension worldwide has doubled in the last 30 years, from 650 million to 1.3 billion.5 The global burden of the disease is increasing mainly due to aging of the society and growing prevalence of obesity.8

Increase in both systolic and diastolic blood pressure values is proportional to the increase in CV risk starting from values of 115/75 mm Hg, while antihypertensive treatment is related to a considerable risk improvement.9,10

According to the most recent data, the prevalence of hypertension in Poland varied from 33% in 2011 to 43% in the years 2013–2014, while an opportunistic cross-sectional survey carried out in 146 sites in May 2018 showed a prevalence of 33%.11-13 No up-to-date nation-wide data on hypertension prevalence in Poland are available. Moreover, the COVID-19 pandemic could have significantly influenced both prevalence and incidence of the disease. Therefore, the aim of this analysis was to estimate the incidence and prevalence of registered hypertension in Poland in the years 2018–2022.

Patients and methods

Data on patients with a diagnosis of hypertension were derived from the public payer claims database. Hypertension was defined using the International Classification of Diseases, 10th Revision (ICD-10) codes from I10 to I15. Patients considered to have hypertension had to meet inclusion criteria defined as at least 1 report of an ICD-10 code I10–I15 from a specialist outpatient clinic or a hospital, or at least 2 reports of an I10–I15 code from a primary care center, starting from January 1, 2009. The analysis was restricted to patients identified by the Polish National Identification Number (PESEL).

A new case of hypertension was defined as the first record of an I10 to I15 code in the national payer claims database. Incidence rate was defined as the number of new cases of hypertension during a year divided by the number of all inhabitants as of December 31 of each year, and expressed in terms of per 100 000 persons per year. Prevalence was defined as all patients with hypertension registered and alive on December 31 of a given year divided by the number of all inhabitants as of December 31 of that year, also per 100 000 persons. The structure of the Polish population was obtained from the Statistics Poland database.14 The analyses were performed across age and sex groups.

Ethics committee approval was not needed, as we analyzed a national database. Informed consent was not required.

Statistical analysis

Continuous variables are presented as means (SD), whereas discrete variables are shown as percentages. We calculated 95% CIs of both continuous and discrete variables using the adjusted Wald method. The Pearson χ2 test was applied to all categorical variables. Continuous variables were compared using the t test or analysis of variance, as appropriate. A P value below 0.05 was considered significant. The R version 3.6.2 (open-source and free software, licensed by the GNU Project) and Microsoft Excel 365 (Microsoft Corporation, Redmond, Washington, United States) were used for all calculations.

Results

Altogether, between 10.9 million and 11 million cases of hypertension were registered during the study period (6–6.1 million in women and 4.8–4.9 million in men) (Table 1). The total number of cases increased from 10.8 million in 2018 to 11 million in 2020, and then decreased to 10.9 million in the years 2021–2022. The incidence rate was lower in 2020–2022 than in 2018–2019 (Table 1, Figure 1). The number of children (age <⁠18 years) with registered hypertension was 34 100, 34 100, 32 100, 31 300, and 30 700, while the number of adults (age ≥18 years) was 10.8 million, 11 million, 10.9 million, 10.9 million, and 10.9 million in 2018, 2019, 2020, 2021, and 2022, respectively.

Table 1. Number of cases, incidence, and prevalence of registered hypertension in Poland in the years 2018–2022

Year

2018

2019

2020

2021

2022

Number of cases (95% CI)

Total

10 846 299 (10 840 720–10 851 879)

10 984 132 (10 978 532–10 989 733)

10 955 074 (10 949 482–10 960 667)

10 919 292 (10 913 716–10 924 869)

10 901 819 (10 896 248–10 907 391)

Men

4 796 134 (4 792 362–4 799 907)

4 888 030 (4 884 235–4 891 826)

4 886 339 (4 882 547–4 890 132)

4 884 996 (4 881 211–4 888 782)

4 888 734 (4 884 950–4 892 519)

Women

6 050 165 (6 046 064–6 054 266)

6 096 102 (6 091 993–6 100 211)

6 068 735 (6 064 634–6 072 837)

6 034 296 (6 030 210–6 038 383)

6 013 085 (6 009 004–6 017 166)

Incidence per 100 000 (95% CI)

Total

1140.9 (1137.4–1144.4)

1158.3 (1154.8–1161.8)

888.3 (885.3–891.4)

973.7 (970.5–976.9)

873.8 (870.8–876.9)

Men

1235.9 (1230.7–1241.1)

1263.1 (1257.9–1268.4)

945.1 (940.6–949.7)

1036.6 (1031.8–1 041.4)

906.6 (902.1–911)

Women

1051.9 (1047.2–1056.5)

1060.1 (1055.4–1064.7)

835.1 (831–839.3)

914.9 (910.5–919.2)

843.2 (839.1–847.4)

Prevalence per 100 000 (95% CI)

Total

28 237.4 (28 222.8–28 251.9)

28 617.5 (28 602.9–28 632.1)

28 629.5 (28 614.9–28 644.1)

28 804.9 (28 790.2–28 819.7)

28 829.9 (28 805.2–28 834.7)

Men

25 810.8 (25 790.5–25 831.1)

26 326.4 (26 305.9–26 346.8)

26 409.4 (26 389–26 429.9)

26 660.6 (26 639.9–26 681.2)

26 742.0 (26 721.3–26 762.7)

Women

30 511.3 (30 490.6–30 532)

30 764.3 (30 743.5–30 785.0)

30 707.9 (30 687.2–30 728.7)

30 811.1 (30 790.3–30 832)

30 763.4 (30 742.5–30 784.3)

Figure 1. Incidence of registered hypertension in Poland in the years 2018–2022 by age groups (P values for comparison between years indicated by the χ2 statistics)

The incidence of registered hypertension among children was 91.1, 88.6, 58, 67.2, and 69.3 per 100 000 (P <⁠0.001), while the incidence among adults was 1372, 1394.7, 1072.7, 1178.7, and 1055.7 per 100 000 (P = 0.002) in 2018, 2019, 2020, 2021, and 2022, respectively. The prevalence of hypertension increased in all age groups in the years 2018–2022 (Figure 2). The highest incidence of hypertension was noted in men aged 55–59 years and in women aged 50–54 years (Table 2; Supplementary material, Figures S1 and S2), while prevalence was the highest in the oldest age groups in both sexes (Table 3, Figure 3; Supplementary material, Figures S3 and S4). The prevalence of registered hypertension among children was 491.3, 490.5, 461.3, 447, and 440.8 per 100 000 (P <⁠0.001), while among adults it was 34 351.1, 34 835.2, 34 885.1, 35 219.2, and 35 234.9 per 100 000 (P <⁠0.01) in 2018, 2019, 2020, 2021, and 2022, respectively.

Figure 2. Prevalence of registered hypertension in Poland in the years 2018–2022 by age groups (P values for comparison between years indicated by the χ2 statistics)

Table 2. Number of new cases and incidence (per 100 000) of registered hypertension in Poland in 2022, stratified by age and sex

Age groups, y

All

Men

Women

New cases (95% CI)

Incidence (95% CI)

New cases (95% CI)

Incidence (95% CI)

New cases (95% CI)

Incidence (95% CI)

0–4

238 (207–271)

13.2 (11.5–15)

140 (116–166)

15.1 (12.5–17.9)

98 (78–120)

11.1 (8.9–13.6)

5–9

470 (427–515)

23.9 (21.7–26.2)

275 (242–310)

27.2 (23.9–30.7)

195 (167–225)

20.4 (17.4–23.5)

10–14

1813 (1728–1900)

86.8 (82.7–91)

1069 (1004–1136)

99.8 (93.7–106.1)

744 (689–801)

73.2 (67.8–78.7)

15–19

3985 (3859–4113)

221 (214–228.1)

2629 (2527–2733)

284.5 (273.5–295.8)

1356 (1282–1432)

154.3 (145.9–162.9)

20–24

4760 (4622–4900)

256.5 (249–264)

2996 (2887–3107)

316.5 (305–328.3)

1764 (1680–1850)

194 (184.8–203.4)

25–29

7767 (7591–7945)

349 (341.1–357)

4764 (4626–4904)

421.3 (409.1–433.6)

3003 (2894–3114)

274.4 (264.3–284.5)

30–34

13 650 (13 417–13 885)

506.5 (497.9–515.2)

8191 (8011–8373)

598.3 (585.1–611.6)

5459 (5312–5608)

411.7 (400.6–423)

35–39

23 308 (23 004–23 614)

740.9 (731.2–750.6)

13 483 (13 252–13 716)

846.2 (831.7–860.8)

9825 (9627–10 025)

632.8 (620.1–645.7)

40–44

33 316 (32 953–33 681)

1074 (1062.3–1085.7)

18 199 (17 931–18 469)

1162.7 (1145.5–1179.9)

15 117 (14 872–15 364)

983.7 (967.7–999.7)

45–49

40 858 (40 457–41 261)

1446.4 (1432.2–1460.7)

20 794 (20 508–21 082)

1467.1 (1446.9–1487.4)

20 064 (19 783–20 347)

1425.7 (1405.7–1445.8)

50–54

40 584 (40 185–40 985)

1739.1 (1722–1756.3)

19 490 (19 213–19 769)

1682.2 (1658.3–1706.3)

21 094 (20 806–21 384)

1795.3 (1770.8–1820)

55–59

37 971 (37 585–38 359)

1705.9 (1688.5–1723.3)

18 612 (18 341–18 884)

1715.3 (1690.3–140.4)

19 359 (19 083–19 637)

1697 (1672.8–1721.4)

60–64

41 301 (40 898–41 706)

1653.2 (1637–1669.4)

19 748 (19 469–20 029)

1680.6 (1656.9–1704.5)

21 553 (21 262–21 846)

1628.8 (1606.8–1650.9)

65–69

37 580 (37 195–37 967)

1501.5 (1486.1–1516.9)

17 089 (16 830–17 350)

1521.6 (1498.5–1544.9)

20 491 (20 207–20 777)

1485.1 (1464.5–1505.8)

70–74

24 211 (23 902–24 522)

1199.6 (1184.3–1215.1)

10 380 (10 177–10 584)

1220.1 (1196.3–1244.1)

13 831 (13 597–14 067)

1184.8 (1164.7–1205)

75–79

10 426 (10 223–10 631)

923.7 (905.7–941.9)

4506 (4372–4642)

1028.2 (997.7–1059.1)

5920 (5767–6075)

857.4 (835.2–879.8)

80–84

5106 (4964–5250)

628.2 (610.7–646)

2166 (2073–2261)

786.9 (753.2–821.3)

2940 (2832–3050)

547 (526.9–567.5)

≥85

3204 (3091–3319)

404.3 (390–418.8)

1199 (1130–1270)

547.3 (515.8–579.8)

2005 (1916–2096)

349.7 (334.1–365.6)

Total

330 548 (329 395–331 705)

873.8 (870.8–876.9)

165 730 (164 914–166 550)

906.6 (902.1–911)

164 818 (164 05–165 635)

843.2 (839.1–847.4)

Table 3. Number of cases and prevalence (per 100 000) of registered hypertension in Poland in 2022, stratified by age and sex

Age groups, y

All

Men

Women

Cases (95% CI)

Prevalence (95% CI)

Cases (95% CI)

Prevalence (95% CI)

Cases (95% CI)

Prevalence (95% CI)

0–4

858 (799–918)

47.5 (44.2–50.8)

494 (449–540)

53.2 (48.4–58.2)

364 (325–404)

41.4 (37–46)

5–9

3824 (3700–3949)

194.4 (188.1–200.8)

2168 (2074–2263)

214.7 (205.5–224.1)

1656 (1574–1739)

173.1 (164.6–181.8)

10–14

12 005 (11 786–12 225)

574.9 (564.4–585.4)

6757 (6593–6922)

630.6 (615.3–646.1)

5248 (5103–5394)

516.1 (501.9–530.5)

15–19

27 288 (26 960–27 617)

1513.5 (1495.3–1531.8)

16 881 (16 623–17 140)

1827 (1799.2–1855.1)

10 407 (10 204–10 611)

1184 (1160.9–1207.3)

20–24

56 529 (56 060–56 999)

3045.9 (3020.6–3071.2)

36 333 (35 959–36 708)

3838.4 (3798.9–3878.1)

20 196 (19 914–20 478)

2220.9 (2190–2252)

25–29

105 128 (104 495–105 762)

4723.9 (4695.5–4752.4)

68 168 (67 661–68 675)

6028 (5983.2–6072.9)

36 960 (36 582–37 339)

3376.6 (3342.1–3411.3)

30–34

183 017 (182 190–183 844)

6791.2 (6760.6–6821.9)

117 864 (117 207–118 522)

8609 (8561.1–8657.1)

65 153 (64 655–65 652)

4914.1 (4876.5–4951.8)

35–39

317 143 (316 074–318 212)

10 081.1 (10 047.1–10 115.1)

199 076 (198 241–199 912)

12 494.3 (12 441.9–12 546.7)

118 067 (117 406–118 729)

7604.6 (7562–7647.2)

40–44

481 109 (479 833–482 385)

15 509.1 (15 468–15 550.2)

287 368 (286 399–288 337)

18 358.7 (18 296.9–18 420.7)

193 741 (192 918–194 565)

12 606.6 (12 553–12 660.2)

45–49

680 062 (678 624–681 500)

24 075.3 (24 024.4–24 126.2)

378 420 (377 366–379 474)

26 698.7 (26 624.4–26 773.1)

301 642 (300 668–302 616)

21 433.3 (21 364.1–21 502.5)

50–54

815 300 (813 843–816 757)

34 937.9 (34 875.5–35 000.4)

420 014 (418 979–421 049)

36 251.7 (36 162.4–36 341.1)

395 286 (394 261–396 310)

33 642.5 (33 555.3–33 729.7)

55–59

1 009 947 (1 008 461–1 011 432)

45 373.3 (45 306.6–45 440)

490 577 (489 540–491 614)

45 210.8 (45 115.2–45 306.4)

519 370 (518 306–520 433)

45 527.9 (45 434.6–45 621.1)

60–64

1 393 255 (1 391 684–1 394 824)

55 768.5 (55 705.6–55 831.3)

642 742 (641 662–643 821)

54 699.9 (54 608–54 791.7)

750 513 (749 373–751 652)

56 717.4 (56 631.2–56 803.5)

65–69

1 729 564 (1 728 101–1 731 025)

69 102.6 (69 044.2–69 161)

757 098 (756 104–758 090)

67 411.4 (67 322.9–67 499.8)

972 466 (971 394–973 536)

70 479.3 (70 401.6–70 556.9)

70–74

1 622 038 (1 620 909–1 623 165)

80 371.6 (80 315.7–80 427.5)

661 122 (660 354–661 888)

77 708.3 (77 618.1–77 798.4)

960 916 (960 091–961 739)

82 312.6 (82 241.9–82 383.1)

75–79

1 017 997 (1 017 364–1 018 627)

90 189.6 (90 133.6–90 245.4)

380 236 (379 787–380 683)

86 763.9 (86 661.6–86 866)

637 761 (637 319–638 200)

92 363.8 (92 299.9–92 427.5)

80–84

717 733 (717 153–718 310)

88 309.7 (88 238.5–88 380.8)

232 538 (232 158–232 916)

84 483.1 (84 345.1–84 620.6)

485 195 (484 760–485 627)

90 269.3 (90 188.5–90 349.9)

≥85

729 022 (728 538–729 503)

91 994.2 (91 933.2–92 055)

190 878 (190 564–191 189)

87 132.2 (86 989.2–87 274.7)

538 144 (537 780–538 506)

93 851.7 (93 788.3–93 914.9)

Total

10 901 819 (10 896 249–10 907 391)

28 819.9 (28 805.2–28 834.7)

4 888 734 (4 884 950–4 892 529)

26 742 (26 721.3–26 762.7)

6 013 085 (6 009 005–6 017 167)

30 763.4 (30 742.5–30 784.3)

Figure 3. Proportions of patients with registered hypertension in relation to the total Polish population as of December 31, 2022

The mean (SD) age of individuals with registered hypertension was 63.1 (14.7), 63.3 (14.7), 63.5 (14.7), 63.6 (14.7), and 63.8 (14.6) in the general population (P <⁠0.001), 65.5 (14.1), 65.7 (14.1), 65.9 (14.1), 66 (14.1), and 66.2 (14.1) in women (P <⁠0.001), and 60.1 (14.9), 60.3 (14.9), 60.5 (14.8), 60.6 (14.8), and 60.8 (14.8) in men (P <⁠0.01), respectively, in 2018, 2019, 2020, 2021, and 2022. The mean (SD) age at the time of hypertension diagnosis was 53.1 (14.9), 52.9 (14.7), 53.3 (14.6), 53 (14.5), and 53.3 (14.6) in the general population (P <⁠0.001), 54.5 (14.4), 54.4 (14.3), 54.5 (14.2), 54.3 (14), and 54.9 (14.3) in women (P <⁠0.001), and 51.8 (15.1), 51.6 (15), 52.1 (14.8), 51.7 (14.7), and 51.8 (14.9) in men (P = 0.24) in 2018, 2019, 2020, 2021, and 2022, respectively.

The incidence of registered hypertension was the highest in the Podlaskie voivodeship and the lowest in the Pomeranian voivodeship (Figure 4), while prevalence was the highest in the Łódź voivodeship and the lowest in the Lesser Poland voivodeship (Figure 5).

Figure 4. Incidence of registered hypertension in Poland in 2022 by voivodeships. Values in parentheses represent 95% CIs.

Figure 5. Prevalence of registered hypertension in Poland in 2022 by voivodeships. Values in parentheses represent 95% CIs.

Discussion

Incidence and prevalence rates, determined respectively as the number of new cases of a given disease and the number of individuals affected by that disease within a unit of time relative to the general population, are among the most important measures for evaluating the health status of large populations.15 These data can be collected within representative epidemiologic studies or through registries gathering specific diagnoses, which involve patients seeking health care or undergoing a diagnostic process. A major limitation of epidemiologic studies is often low response rate of the randomized sample of the population. The representativeness of the randomized sample may also be an issue. On the other hand, an advantage is that undiagnosed cases are usually taken into account. A strength of the claims data analyses is that they include virtually all cases of the disease reported to the national payer database. However, such data usually do not capture undiagnosed and unreported cases. In addition, the reliability of such analyses is based on the robustness of the claims data and public database used.

The estimations of hypertension prevalence in Poland varied from 33% to 43% in adults.11-13 It has been shown that hypertension remains undiagnosed in about 20% to 40% of the general population.12 This finding may result from several important factors. Easy-to-administer screening methods, for example, office-based blood pressure measurement, are characterized by low reliability and accuracy, while more reliable and accurate methods are costly and difficult to execute.16 In addition, every 10th patient, despite receiving a diagnosis, does not initiate any treatment.17 Completeness of the reported data also has an impact on the recorded incidence and prevalence. Indeed, it may vary from 60% to 80%.18,19

In this study, a comprehensive assessment of registered incidence and prevalence rates of hypertension in Poland was carried out between 2018 and 2022. It confirmed an increase in the registered prevalence of hypertension with age, which aligns with results of other international reports. Data from the National Center for Health Statistics,20 as well as the results of the current study, indicate that the highest proportion of patients with hypertension is observed in the population aged over 60 years (74.5%). Similar conclusions were drawn by Lloyd-Jones et al,21 who reported prevalence of hypertension at 27% in patients younger than 60 years and 74% in individuals older than 80 years. In the PolSenior (2007–2010) and PolSenior2 (2018–2019) studies,22,23 encompassing patients aged over 65 years, hypertension was found in 76% of the surveyed population.

We observed a 2-fold higher incidence rate in men than in women in the younger age groups. This was also confirmed by the mean age of individuals diagnosed with hypertension, which was 60.8 years among men and 66.2 years among women. In comparison, the mean age at the time of first diagnosis of the disease and its reporting to the national payer database was 51.8 years and 54.9 years, respectively; significantly higher than in the United States, where hypertension was detected on average at the age of 46 years.24 This may suggest a high rate of undetected hypertension among young inhabitants of Poland.

We found a significant drop in the incidence of reported hypertension in 2020. This could be caused by the COVID-19 pandemic, which was paralleled by a limited access to health care professionals and medical procedures as well as delayed reporting of symptoms due to fear of infection.25-27 We showed significant differences in the prevalence of registered hypertension between 2018 and 2022. This could be linked to data regarding mortality from CVDs in Poland during this period. The CV mortality rate was 437.2 per 100 000 in 2018 and 426.2 per 100 000 in 2022.28 Significant differences in the use of antihypertensive drugs during the COVID-19 pandemic were also shown.29

We noted a higher number of women with hypertension, as compared with men, with higher prevalence starting from the age of 55 years. These sex-related differences in the reported hypertension incidence and prevalence could be influenced by the disparity in the frequency of medical care usage between women and men. Indeed, men see physicians significantly less often than women.30

The present analysis disclosed a considerable territorial variation in both the incidence and prevalence of registered hypertension. The highest morbidity rate was noted in the Łódź voivodeship. This finding is in line with data on the health profile of the region characterized by negative health status indicators and the shortest average life expectancy, both for women and men.2 Conversely, the highest incidence rates were observed in the Podlaskie and Lubelskie voivodeships, which may indicate an unfavorable epidemiologic situation in these areas. On the other hand, it may have also been caused by improvements in hypertension detection in these regions in recent years.

Limitations

The current analysis has several limitations. The COVID-19 pandemic broke out during the analyzed period, which could have significantly affected both detectability and reporting of the disease. On the other hand, we were able to assess changes in the incidence and prevalence of hypertension during the pandemic. Due to the design of the study, we could not assess the rate of undiagnosed hypertension in the population. We had no access to data of patients using only private services. In addition, we could have missed patients with diagnosed hypertension who were not using medical care. As a consequence, the actual prevalence of hypertension in the Polish population may be even higher than estimated in the present study. We were unable to analyze patient lifestyles or the prescription rates for cardioprotective drugs. The inclusion of such data in the present analysis could have increased the impact of our results. Finally, the reliability of our results is based on the robustness of the public database we used, including the reporting bias resulting from the specificity of financing claims.

Conclusions

The number of patients with registered hypertension in Poland reaches 11 million. In 2022, the registered prevalence of hypertension was 35.2% in adults and 0.4% in children. In the population aged up to 55 years, the prevalence is higher in men, whereas in older age groups it is higher in women. We found a drop in the incidence of registered hypertension during the COVID-19 pandemic.