Table 4

Validation of diagnoses in the Swedish Inpatient Register by sensitivity

Diagnosis

Proportion identified through the IPR (%) (sensitivity)

Comment

Main Author

PubMed ID

Year

Gold Standard (Reference)


Cardiovascular disease

Myocardial Infarction (MI)

54/59 (91.5)

Cross-sectional, 1-year retrospective study. ≥20 year-olds from Degerfors area.

Elo [14]

19084244

2009

Data were obtained from IPR, hospital-based outpatient care and primary health care

Myocardial infarction

99/128 (77)

Merlo [63]

10870938

2000

Men born 1914

Myocardial infarction

113/144 (79)

Merlo [63]

10870938

2000

The Skaraborg Hypertension Study

Myocardial Infarction

3201/4148 (77.2)

The researchers identified all MIs in Stockholm county in 1973 through the local IPR and the national Cause of Death Register (restricted to individuals living in Stockholm).

Ahlbom [64]

721364

1978

Swedish Cause of Death Register

Myocardial infarction

4746/5832 (81.4) of MI cases in community registers were found in IPR or the Cause of Death Register.

IPR and Cause of Death Register data from 1972-1981 for regions with IPR registers at the time. 81% of cases in community registers were found in IPR or Cause of Death Register. Meanwhile 85% of cases in IPR and the Cause of Death Register were found in Community registers (disregarding non-matching fatal cases).

Hammar [65]

2066207

1991

Community registers with myocardial infarctions

Angina Pectoris

86/196 (43.9)

Cross-sectional, 1-year retrospective study. ≥20 year-olds from Degerfors area.

Elo [14]

19084244

2009

Data were obtained from IPR, hospital-based outpatient care and primary health care

Acute coronary syndrome (MI or unstable angina pectoris)

IPR from emergency department missed 2% of 218 patients with acute coronary syndrome.

Discharge diagnoses from emergency department, Lund University Hospital.

Forberg [66]

18804783

2009

MR. The study evaluates different methods to identify acute coronary syndrome in patients, using information not available in the IPR (e.g. ECG measurements).

Non-specified ischemic heart disease

44/206 (21.4)

Cross-sectional, 1-year retrospective study. ≥20 year-olds from Degerfors area.

Elo [14]

19084244

2009

Data were obtained from IPR, hospital-based outpatient care and primary health care

Stroke (non-subarachnoidal hemorrhage)

318/377 (84.4)

Data from a local stroke incidence study at the Örebro University Hospital.

Appelros

-

(PC, Feb 22)

Local stroke incidence study

Non-fatal strokes

3492/3732 (93.6) of all cases

3492/3562 (98.0) of estimated hospital cases

Patients aged 25-74 years in 1985-89. Criteria for acute stroke from MONICA study were comparable to WHO criteria.

Stegmayr [38]

1291884

1992

MONICA-population based stroke register

Stroke

75/79 (95)

Merlo [63]

10870938

2000

The Skaraborg Hypertension Study

Stroke

76/81 (94)

Merlo [63]

10870938

2000

"Men born 1914"

Stroke

384/456 (84.2)

First-time stroke. Restricted to the Lund county.

Hallström [67]

17156265

2007

*

Stroke/Transient ischemic A.

217/232 (93.5)

ULSAM.

Wiberg

-

(PC, Feb 12)

ULSAM

Hypertension

5,886/42,796 (13.7)

IPR data from the county Östergötland.

Wiréhn [68]

17786807

2007

County registers of primary health care, outpatient hospital care and inpatient care

Hypertension

74/838 (8.8)

Cross-sectional, 1-year retrospective study. ≥20 year-olds from Degerfors area.

Elo [14]

19084244

2009

Data were obtained from IPR, hospital-based outpatient care and primary health care

Gestational

hypertension

108/166 (65.1)

Zetterström

-

(PC, March 3)

All pregnant women in Sweden have their blood pressure examined.

Lipid disorders

19/186 (10.2)

Cross-sectional, 1-year retrospective study. ≥20 year-olds from Degerfors area.

Elo [14]

19084244

2009

Data were obtained from IPR, hospital-based outpatient care and primary health care

Autoimmune/immune-mediated diseases

Rheumatoid arthritis (RA)

489/1150 (42.5)

Malmö, Sweden, 1990-1994. According to the RA criteria of the American College of Rheumatology [41].

Turesson [42]

10461483

1999

Data from all rheumatologists and general practictioners in Malmö city, 1997

Diabetes, type 1 and 2*

92/394 (23.3)

Cross-sectional, 1-year retrospective study. ≥20 year-olds from Degerfors area.

Elo [14]

19084244

2009

Data were obtained from IPR, hospital-based outpatient care and primary health care

Type 1 and type 2 diabetes mellitus *

349/436 (80.0) patients with diabetes in "source 1" could be identified in the IPR

The researchers evaluated the presence of type 1 or type 2 diabetes among patients with atrial fibrillations at the Södersjukhuset Hospital. All but 8 patients in this validation had type 2 diabetes.

Friberg

-

(PC, Feb 8)

MR + biochemistry data + data on insulin or other medication against diabetes

Type 1 and type 2 diabetes mellitus*

4,348/18,134 (24.0)

IPR data from the county Östergötland.

Wiréhn [68]

17786807

2007

County registers of primary health care, outpatient hospital care and inpatient care

Both type 1/2 diabetes and foot ulcer

235/280 (83.9) admissions could be identified through the IPR

Based on 117 patients with deep foot infections and type 1 or 2 diabetes, referred to multidisciplinary foot-care team. Specificity for foot ulcers and concomitant diabetes was 98%.

Ragnarson- Tennvall [46]

11123504

2000

MR

Infectious disease

CNS infection in intensive care

ICD-9: 21/22 (95.4)

ICD-10: 21/28 (75.0)

Specificity was 99.6% (ICD-9) and 99.7% (ICD-10). IPR data obtained through both primary and secondary diagnoses.

Gedeborg [69]

17208121

2007

ICU database diagnoses as reference

Pneumonia in intensive care

ICD-9: 89/185 (48.1)

ICD-10: 116/221 (52.5)

Specificity was 95.9% (ICD-9) and 95.8% (ICD-10). IPR data obtained through both main and secondary diagnoses.

Using only primary diagnoses for pneumonia the specificity increased slightly but the sensitivity decreased to 31.2% and 38.2% respectively.

Gedeborg [69]

17208121

2007

ICU database diagnoses as reference

Sepsis in intensive care

ICD-9: 85/186 (45.7)

ICD-10: 94/179 (52.5)

Specificity was 97.5% (ICD-9) and 92.6% (ICD-10). IPR data obtained through both main and secondary diagnoses.

Gedeborg [69]

17208121

2007

ICU database diagnoses as reference, with inclusion in sepsis trials (IST) as secondary reference

Tuberculosis

12/15 (80)

Evaluation in patients with concomitant rheumatoid arthritis

Askling [70]

15986370

2005

MR

Other disorders

Carotid, infrainguinal bypass and aortic aneurysm (AAA) procedures

10,861/11,638 (93.3) of patients identified through Swedvasc (Svenska kärlregistret) or the IPR could be identified in the IPR

(Swedvasc) started in 1987 and became nationwide 1994. In the paper by Troëng et al data on infraingunal and carotid bypass originated from 5 years (2000-2004), while data on aortic aneurysms originated from 1 year (2006). Divided the sensitivity figures were: Carotid 96.8%; Infrainguinal 92.3% and aortic aneurysm 88.9%.

Troëng [15]

And by

18851920

2008

The Swedish Vascular Register (Swedvasc)

Asthma

1,377/18,451 (7.5)

IPR data from the county Östergötland.

Wiréhn [68]

17786807

2007

County registers of primary health care, outpatient hospital care and inpatient care

Dementia

23/87 (26)

Participants originated from the study "Aging in women and men: a longitudinal study of gender differences in health behaviour and health among the elderly (as part of the Swedish Twin Register). The specificity for dementia was 97% (399/411)

Dahl [71]

18007116

MR + memory test scores etc.

Dementia

41.3% for prevalent cases and 42.3% for incident cases.

Participants originated from the study "Aging in women and men: a longitudinal study of gender differences in health behaviour and health among the elderly (as part of the Swedish Twin Register). The specificity for dementia was 97% (399/411)

Rizutto

(PC, May 14)

Comparison between cases detected in IPR with cases derived from the Kungsholmen (KP) and SNAC-K Projects [72]

Foot ulcer (only)

249/280 (88.9%) of admissions could be identified through the IPR

Based on 117 patients with deep foot infections and type 1 or 2 diabetes, referred to multidisciplinary foot-care team.

Ragnarson- Tennvall [46]

11123504

2000

MR

Chronic obstructive pulmonary disease

1,290/4,812 (26.8)

IPR data from the county Östergötland.

Wiréhn [68]

17786807

2007

County registers of primary health care, outpatient hospital care and inpatient care


PC, Personal communication: All personal communications took place in 2010 (exact date is listed in the table).

ICU, Intensive Care Unit. MI, Myocardial Infarction. MR, compared with Medical Records (patient charts). RA, Rheumatoid arthritis.

ULSAM, Uppsala Longitudinal Study of Adult Men) cohort.

*Data from all departments at the Lund Hospital including the emergency unit, general practitioners, community nurses, physicians at the Neurology department, autopsy registers, Forensic department, computerized searches of outpatient medical records

Ludvigsson et al. BMC Public Health 2011 11:450   doi:10.1186/1471-2458-11-450

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