The Swedish Primary Care Cardiovascular Database (SPCCD): 74 751 hypertensive primary care patients

Figures & data

Table I. Variables in the Swedish Primary Care Cardiovascular Database (SPCCD).

Variables	Description
Patients	Anonymous identification number, age, sex
Contacts with caregivers	Dates and type of contact, caregiver (physicians, registered nurses)
Clinical data	Body weight and height, all recorded systolic and diastolic blood pressures and structured recorded data on smoking habits
Blood and urine laboratory analyses	Fasting total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides and glucose, creatinine, HbA1c and microalbuminuria
Diagnoses in primary care (ICD-10 codes)	Hypertension (I10, I13P and I15), atrial fibrillation/flutter (I48), congestive heart failure (I50), diabetes mellitus (E10-11, E14), ischaemic heart disease (I20–25), ischaemic and haemorrhagic stroke (I60–69), transient ischaemic attack (G45)
Prescribed drugs (ATC codes)	Angiotensin-converting enzyme inhibitors C09A, C09B; angiotensin receptor blockers C09C, C09D; beta adrenergic receptor blockers C07; calcium channel blockers C08; diuretics, C03 (including thiazides, loop diuretics and spironolactone)
All prescriptions dispensed for all drugs July 2005–December 2009	ATC code, date and amount of drugs, prescriber and healthcare provider
All hospitalizations; all consultations in hospital-based outpatient care	Date of admission, discharge and consultation up to eight recorded ICD-10 diagnoses per occasion for in-hospital (1997–2009) and out-patient (2001–2009) care
Date and cause of death	Date of death, cause of death (main and contributing), ICD-10 codes
Level of education, in 2005 and 2009	Low (9 years or less of schooling, elementary); Medium, two levels (10–12 years, secondary school); High, three levels (> 12 years, post-gymnasium education)
Country of birth; residence of patients	Sweden, other Nordic countries, the EU27 or countries in the rest of the world. Place of residence per year from 2004 (municipality)

LDL, low-density lipoprotein; HDL, high-density lipoprotein; HbA1c; glycosylated haemoglobin; ICD-10, International Classification of Diseases, version 10; ATC, anatomic therapeutic chemical classification system; EU27, Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, The Netherlands, UK.

Figure 1. Sources contributing with data in Swedish Primary Care Cardiovascular Database.

Figure 2. Flowchart over patients included in the Swedish Primary Care Cardiovascular Database (SPCCD). In Stockholm 1609 patients and in Skaraborg 1204 patients attended more than one primary healthcare centre.

Figure 3. Age distribution according to sex of the patients in the Swedish Primary Care Cardiovascular Database. The patients presented are those with recorded blood pressures in 2008; the age is given for 2001. The mean blood pressure for men (n = 32 184) was 143/81 ± 18/11 mmHg and for women (n = 40 845) 144/80 ± 19/11 mmHg. The last recorded blood pressure in age groups 30–49 years (n = 11 529), 50–70 years (n = 38 704), and > 70 years (n = 22 796) were 140/86 ± 17/10, 143/81 ± 17/10 and 146/77 ± 21/11 mmHg, respectively.

Table II. Clinical characteristics of individuals in the Swedish Primary Care Cardiovascular Database (SPCCD), 2001–2008.

	All SPCCD			Stockholm		Skaraborg
	Women	Men	All	Women	Men	Women	Men
n (2001–2008)	41 728	33 023	74 751	22 172	17 257	39 429	19 556
n (with BP recordings 2008)	26 452	20 485	46 937	13 655	10 190	12 797	10 295
Mean± SD of values
Age, years	71.0 ± 13.7	67.8 ± 12.9	69.6 ± 13.4	69.7 ± 14.0	66.5 ± 13.0	72.5 ± 13.2	69.2 ± 12.7
BMI, kg/m^2	29.0 ± 5.6	28.8 ± 4.6	28.9 ± 5.2	29.5 ± 5.8	29.1 ± 4.9	28.8 ± 5.5	28.7 ± 4.5
Tot-cholesterol, mmol/l	5.5 ± 1.1	5.1 ± 1.0	5.4 ± 1.1	5.6 ± 1.1	5.2 ± 1.1	5.5 ± 1.1	5.1 ± 1.0
HDL cholesterol, mmol/l	1.6 ± 0.4	1.3 ± 0.4	1.4 ± 0.4	1.5 ± 0.4	1.3 ± 0.4	1.6 ± 0.4	1.3 ± 0.4
LDL cholesterol, mmol/l	3.2 ± 0.9	3.1 ± 0.9	3.2 ± 0.9	3.3 ± 0.9	3.1 ± 0.9	3.2 ± 0.9	3.0 ± 0.9
Triglycerides, mmol/l	1.5 ± 0.8	1.7 ± 1.0	1.6 ± 0.9	1.5 ± 0.8	1.7 ± 1.1	1.5 ± 0.7	1.6 ± 0.9
P-glucose, mmol/l	6.2 ± 2.1	6.5 ± 2.3	6.4 ± 2.2	6.2 ± 2.3	6.7 ± 2.7	6.2 ± 1.8	6.5 ± 2.0
Creatinine, mmol/l	75.5 ± 29.9	91.9 ± 37.7	82.7 ± 34.5	73.5 ± 27.8	90.5 ± 36.9	77.7 ± 32.0	93.5 ± 38.4
Co-morbidity, n (%)
Atrial fibrillation	2857 (6.8%)	2926 (8.9%)	5783 (7.7%)	1350 (6.1%)	1424 (8.3%)	1507 (6.8%)	1502 (8.7%)
IHD	5353 (12.8%)	5606 (17.0%)	10 959 (14.7%)	2666 (12.0%)	2644 (15.3%)	2687 (12.1%)	2962 (17.2%)
CHF	3200 (7.7%)	2412 (7.3%)	5612 (7.5%)	1469 (6.6%)	1063 (6.2%)	1731 (7.8%)	1349 (7.8%)
Cerebrovascular disease	2387 (5.7%)	2693 (8.2%)	5080 (6.8%)	1042 (4.7%)	1234 (7.2%)	1345 (6.1%)	1459 (8.5%)
Diabetes mellitus	7934 (19.0%)	8406 (25.5%)	16 340 (21.9%)	4186 (18.9%)	4538 (26.3%)	3748 (16.9%)	3868 (22.4%)
No CVD or diabetes mellitus^a	25 965 (62.2%)	17 380 (52.6%)	43 345 (58.0%)	14 260 (64.3%)	9382 (54.4%)	11 705 (52.8%)	7998 (46.3%)

Data are based on last recorded values for each patient and are mean values± standard deviations, unless stated otherwise. BP, blood pressure; BMI, body mass index; HDL, high-density lipoprotein; LDL, low-density lipoprotein; IHD, ischaemic heart disease; CHF, congestive heart failure; CVD, cardiovascular disease. Hypertension was diagnosed according to the prevailing recommendations at the time for diagnosis (17), from 1999 at blood pressure levels of ≥ 140 and/or ≥ 90 mmHg (18). A diagnosis of diabetes was based on WHO definitions from 1985 (19) and 1997 (20), or ongoing treatment. Diagnoses according to ICD-codes, as stated in the medical records were based on the clinical decision of the primary care physician. ^aSubjects with no diagnosis of atrial fibrillation, ischaemic heart disease, congestive heart failure, cerebrovascular disease or diabetes mellitus were considered to have no cardiovascular disease.

Table III. Country of birth in the study population.

	All SPCCD						Stockholm						Skaraborg
	Women		Men		All		Women		Men		All		Women		Men		All
Country of birth	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a
Sweden	33 506	80.3	26 938	81.6	60 444	80.9	15 565	70.2	12 365	71.7	27 930	70.9	17 941	91.8	14 573	92.4	32 514	92.1
Nordic countries outside Sweden	3660	8.8	2260	6.8	5920	7.9	2731	12.3	1590	9.2	4321	11.0	929	4.8	670	4.2	1599	4.5
Europe outside Nordic countries	2669	6.4	2115	6.4	4784	6.4	2154	9.7	1746	10.1	3900	9.9	515	2.6	369	2.3	884	2.5
Outside Europe	1884	4.5	1705	5.2	3589	4.8	1716	7.7	1552	9.0	3268	8.3	168	0.9	153	1.0	321	0.9
Total	41 719		33 018		74 737		22 166		17 253		39 419		19 553		15 765		35 318

SPCCD, Swedish Primary Care Cardiovascular Database. ^aCalculated as percentage of total by column. Data were recorded for 74 737 of the 74 751 patients. Nordic countries: Denmark, Finland, Iceland, Norway and Sweden.

Table IV. Educational level in the study population.

	All SPCCD						Stockholm						Skaraborg
	Women		Men		All		Women		Men		All		Women		Men		All
Educational level	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a	n	%^a
Low	8832	31.2	8652	36.7	17 484	33.7	4416	31.2	3870	30.3	8286	30.8	4416	31.2	4782	44.3	9198	36.9
Medium	12 598	44.6	10 310	43.7	22 908	44.2	6299	44.6	5958	46.6	12257	45.5	6299	44.6	4352	40.3	10651	42.7
High	6842	24.2	4626	19.6	11 468	22.1	3421	24.2	2960	23.1	6381	23.7	3421	24.2	1666	15.4	5087	20.4
Total	28 272		23 588		51 860		14 136		12 788		26 924		14 136		10 800		24 936

SPCCD, Swedish Primary Care Cardiovascular Database. Data were recorded for 51 860 of the 74 751 patients. Educational level was defined as Low: up to upper secondary level; Medium: post secondary level up to non-university level; High: university degree. ^aCalculated as percentage of total by column.

Table V. Completeness of data in different variables in 74 751 individuals in the Swedish Primary Care Cardiovascular Database (SPCCD).

	Registered, n (%)	Limits for exclusion	Data outside limits (n)	Data outside limits, % of all
Blood pressure values any time during 2001–2008	73 050^a (97.7)	–	–	–
SBP (mmHg)	948 268	SBP< DBP, SBP < 40, SBP > 300	491	0.1
DBP (mmHg)	948 161	SBP< DBP, DBP < 20, DBP > 150	581	0.1
Weight last recorded (kg)	33 324 (44.6)	< 20, > 300	22	0.1
Height last recorded (cm)	25 939 (34.7)	< 100, > 250	26	0.1
BMI (kg/m^2)	26 763 (35.5)	< 10, > 60	25	0.0
Glucose, first mmol/l^b	50 799 (68.0)	< 0.9, > 50	0	0
Glucose, last mmol/l^b	50 982 (62.2)	< 0.9, > 50	0	0
Total cholesterol (mmol/l)^b	60 410 (80.8)	< 1, > 30	1	0.0
LDL cholesterol (mmol/l)^b	41 842 (56.0)	< 0.1, > 20	0	0
HDL cholesterol (mmol/l)^b	45 172 (60.4)	< 0.1, > 10	0	0
Triglycerides (mmol/l)^b	46 454 (62.1)	< 0.1, > 50	0	0
Creatinine (μmol/l)	71 044 (95.0)	< 20, > 2000	4	0.0
Data on smoking	25 435 (34.0)	–	–	–
Data on prescribed drugs	71 426 (95.9)	–	–	–
Data on dispensed drugs^c	71 686 (95.9)	–	–	–
Data on date of death (until 31 July 2011)	11 213 (15.0)	–	–	–
Data on cause of death (until 31 July 2011)	8 591 (11.5)	–	–	–

SBP, systolic blood pressure; DBP diastolic blood pressure; BMI, body mass index either calculated from body weight and length in database (kg/m²) or registered directly; LDL low-density cholesterol; HDL, high-density cholesterol. ^aNo blood pressure values were recorded in the database for 905 patients in Stockholm and for 851 in Skaraborg. ^bGlucose and lipids are fasting values. ^cIncluding prescriptions from other care-givers than primary healthcare from 1 July 2005 to 31 December 2009.

Figure 4. Digit preference of reported systolic (SBP) and diastolic (DBP) blood pressure measurements 2008 in Stockholm (n = 80 554) and in Skaraborg (n = 58 590).

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