Decreasing national trends in diabetic complications hide regional differences: a prospective population-based study using health care registers in Finland

Figures & data

Table 1. Age and sex standardized incidence rates with 95% confidence intervals (CI) of the first acute coronary syndrome (ACS), ischaemic stroke (IS), major lower limb amputation (LLA) and minor LLA per 100,000 person-years among patients with diabetes in Finland from 2010 to 2017.

Year	ACS (n)	Rate (CI)	IS (n)	Rate (CI)	Major LLA (n)	Rate (CI)	Minor LLA (n)	Rate (CI)
2010	5604	1747.9 (1701.4; 1794.6)	3930	1204.3 (1166.0; 1243.0)	427	134.0 (121.1; 146.9)	523	157.3 (143.5; 171.0)
2011	5527	1609.2 (1566.3; 1652.2)	4116	1170.7 (1134.5; 1207.0)	411	117.5 (106.0; 129.0)	492	136.4 (124.2; 148.6)
2012	5778	1575.9 (1535.0; 1617.0)	4388	1177.7 (1142.6; 1212.8)	426	116.5 (105.3; 127.6)	628	166.8 (153.6; 180.0)
2013	5774	1482.6 (1444.1; 1521.0)	4616	1168.2 (1134.3; 1202.1)	485	124.6 (113.4; 135.7)	570	141.5 (129.8; 153.2)
2014	6027	1468.0 (1430.8; 1505.1)	4617	1117.0 (1084.7; 1149.3)	445	108.3 (98.2; 118.4)	632	152.6 (140.7; 164.6)
2015	6195	1449.8 (1413.7; 1485.9)	4608	1072.7 (1041.7; 1103.7)	444	103.8 (94.2; 113.5)	673	155.7 (144.0; 167.5)
2016	6211	1399.6 (1364.8; 1434.5)	4809	1080.8 (1050.2; 1111.3)	443	99.8 (90.5; 109.1)	728	163.5 (151.6; 175.3)
2017	6535	1436.9 (1402.0; 1472.0)	4769	1048.6 (1018.8; 1078.3)	419	92.1 (83.3; 100.9)	711	156.3 (144.8; 167.8)

Table 2. Characteristics of the study population during the periods 2010 to 2013 and 2014 to 2017.

Variable		2010 to 2013	2014 to 2017
Patients at risk at the beginning of the study period		366,490	438,902
Patients at risk at the end of the study period		424,935	468,168
First acute coronary syndrome (n)		22,683	24,968
First ischemic stroke (n)		17,050	18,803
First major lower limb amputation (n)		1749	1751
First minor lower limb amputation (n)		2213	2744
Person years		1,541,503	1,769,276
Age group (%)	0–54	22	21
	55–64	25	22
	65–74	27	30
	75–84	19	20
	85-	6	7
Sex (%)	Men	52	52
	Women	48	48
Type of diabetes (%)	1	13	12
	2	87	88
Charlson Comorbidity Index	Lowest	7	14
	Highest	2	6
Parallel acute coronary syndrome (%)		7	8
Parallel ischemic stroke (%)		8	9
Parallel lower limb amputation (%)		1	1
University hospital district (%)	Helsinki	34	35
	Kuopio	17	17
	Oulu	14	14
	Tampere	18	18
	Turku	16	16

Figure 1. Risk ratios (RR) and odds ratios (OR) with 95% confidence interval (95%CI) derived from best linear unbiased predictions (BLUPs) for the differences in university hospital districts (UHDs) in the incidence of first acute coronary syndrome (ACS), ischaemic stroke (IS), major lower limb amputation (LLA), minor LLA and percentage of major LLA in the first amputation among patients with diabetes in Finland during the years 2010 to 2013 and 2014 to 2017 compared to the model average. Models adjusted for age, sex, type of diabetes, Charlson Comorbidity Index and parallel cardiovascular complications.

Figure 2. Risk ratios (RR) derived from the best linear unbiased predictions (BLUPs) for the differences in hospital districts (HDs) in the incidence of first acute coronary syndrome (ACS), ischaemic stroke (IS), major lower limb amputation (LLA) and minor LLA among patients with diabetes in Finland during the years 2010 to 2013 and 2014 to 2017 compared to the model average. Models adjusted for age, sex, type of diabetes, Charlson Comorbidity Index and parallel cardiovascular complications. The university hospitals districts are marked in the map of the first period and HDs in the map of the second period with following numbers (3) Varsinais-Suomi, (4) Satakunta, (5) Kanta-Häme, (6) Pirkanmaa, (7) Päijät-Häme, 8) Kymenlaakso, (9) Etelä-Karjala, (10) Etelä-Savo, (11) Itä-Savo, (12) Pohjois-Karjala, (13) Pohjois-Savo, (14) Keski-Suomi, (15) Etelä-Pohjanmaa, (16) Vaasa, 17) Keski-Pohjanmaa, (18) Pohjois-Pohjanmaa, (19) Kainuu, (20) Länsi-Pohja, (21) Lappi, (25) Helsinki/Uusimaa.

Table 3. Age-standardized annual trends with 95% confidence intervals (95%CI) in the incidence of first acute coronary syndrome (ACS), ischaemic stroke (IS), major lower limb amputation (LLA), minor LLA and proportion of major LLAs of all first LLAs (MLLA %) by sex among patients with diabetes in Finland during the year 2010 to 2017.

	ACS (%)	IS (%)	Major LLA (%)	Minor LLA (%)	MLLA % (%)
Annual trend in the total population with diabetes	−2.7 (−3.0; −2.3)	−2.0 (−2.4; −1.5)	−4.6 (−5.9; −3.1)	0.9 (−0.4; 2.1)	−8.3 (−10.2; −6.3)
Annual trend in the male population with diabetes	−2.1 (−2.6; −1.6)	−2.1 (−2.8; −1.5)	−4.9 (−6.7; −3.1)	1.4 (−0.1; 2.9)	−9.5(−11.9; −7.0)
Annual trend in the female population with diabetes	−3.4 (−4.0; −2.8)	−1.8 (−2.4; −1.2)	−4.0 (−6.1; −1.7)	−0.3 (−2.4; 1.9)	−6.2 (−9.4; −2.9)
Sex difference in the trend (p-value)	p = .001	p = .429	p = .479	p = .225	p = .092

Figure 3. Average annual trend as risk ratio (RR) or odds ratio (OR) with 95% confidence intervals (95%CI) in the incidence of the first acute coronary syndrome (ACS), ischaemic stroke (IS), major lower limb amputation (LLA) and proportion of major LLAs of all first LLAs among patients with diabetes in Finland during the years 2010 to 2017 in the five university hospital districts compared to the model average.

Table 4. University hospital district (UHD) based comparison of the use of medicines for elevated blood pressure (BP), medicines for elevated cholesterol (CH) and antihyperglycaemic medicines (DM); the numbers and proportions of patients with diabetes using the medicines in 2017.

Medicines	Helsinki	Kuopio	Oulu	Tampere	Turku
BP – no medicines	45,321 27.5%	18,448 23.3%	16,749 25.2%	20,689 25.1%	20,035 27.2%
BP – one medicine	44,723 27.1%	22,199 28.0%	18,554 27.9%	23,044 28.0%	21,007 28.5%
BP – two medicines	46,431 28.2%	24,028 30.3%	19,594 29.5%	23,997 29.1%	20,918 28.4%
BP – three or more medicines	28,291 17.2%	14,558 18.4%	11,597 17.4%	14,640 17.8%	11,793 16.0%
CH – any medicine	90,814 55.1%	44,998 56.8%	35,587 53.5%	40,620 49.3%	36,636 49.7%
CH – any statin	89,889 54.6%	44,441 56.1%	35,100 52.8%	40,197 48.8%	36,258 49.2%
CH – ezetimibe	3807 2.3%	2599 3.3%	2471 3.7%	1458 1.8%	1158 1.6%
DM – no medicines	34,350 20.9%	15,775 19.9%	15,170 22.8%	16,526 20.1%	15,790 21.4%
DM – one medicine	66,178 40.2%	31,388 39.6%	26,119 39.3%	32,484 39.4%	28,110 38.1%
DM – two medicines	41,191 25.0%	19,922 25.1%	15,531 23.2%	20,689 25.1%	18,783 25.5%
DM – three or more medicines	23,047 14.0%	12,148 15.3%	9674 14.6%	12,671 15.4%	11,070 15.0%
DM – insulin	42,319 25.7%	21,363 27.0%	17,448 26.2%	23,414 28.4%	19,723 26.7%
DM – sulfonylurea	3774 2.3%	1220 1.5%	1013 1.5%	1500 1.8%	1742 2.4%
DM – glucagon-like peptide-1 receptor agonist	4858 3.0%	2480 3.1%	1712 2.6%	2693 3.5%	2598 3.5%
DM – sodium/glucose co-transporter 2 inhibitor	13,751 8.4%	7829 9.9%	6217 9.4%	7028 8.5%	5978 8.1%

Data availability statement

Due to data protection legislation in Finland, individual-level data on the study subjects cannot be released.