Background
Methods
Design and setting
Sample selection and data sources
Main outcomes
Independent variables
Variable | Definition | Source |
---|---|---|
Frequency of outpatient care per year, respiratory diagnoses | ||
Contact with GP, respiratory diagnoses | Number of contacts with respiratory diagnoses | KUHR |
Emergency room contacts, respiratory diagnoses | Number of contacts with municipal emergency room | KUHR |
Contact with contract specialist, respiratory diagnoses | Number of contacts | KUHR |
Contact with physiotherapist, respiratory diagnoses | Number of contacts with general physiotherapist, manual physiotherapist, occupational therapist | KUHR |
Outpatient contact with hospital, respiratory diagnoses | Number of contacts | NPR |
Rehabilitation, respiratory diagnoses | Number of out- and inpatient rehabilitation contacts in hospital and private clinics | NPR |
Frequency of healthcare per year, non-respiratory diagnoses | ||
Contact with GP, non-respiratory diagnoses | Number of contacts with non-respiratory diagnoses | KUHR |
Emergency room contacts, non-respiratory diagnoses | Number of contacts with municipal emergency room | KUHR |
Contact with contract specialist, non-respiratory diagnoses | Number of contacts | KUHR |
Contact with physiotherapist, non-respiratory diagnoses | Number of contacts with general physiotherapist, manual physiotherapist, occupational therapist | KUHR |
Outpatient contact with hospital, non-respiratory diagnoses | Number of contacts | NPR |
Rehabilitation, non-respiratory diagnoses | Number of rehabilitation contacts, including home-based and short-term rehabilitation from the municipality | NPR/MEPJ |
Hospital admissions, non-respiratory diagnoses | Number of hospital admissions with non-respiratory diagnoses | NPR |
Outpatient care indicators per year | ||
Continuity of GP care | Continuity of care index (COCI) for GP contact dispersion on scale 0–1. Higher values imply contact with fewer unique GPs, thus better continuity. | KUHR |
Spirometry | Indicator of spirometry performed at least once at GP or contract specialist during the year | KUHR |
Early rehabilitation, respiratory diagnoses | Three categories: Rehabilitation within 30 days following at least one COPD hospital admission; only later rehabilitation (up to 6 months) after COPD hospital admissions; no COPD hospital admissions or admissions with rehabilitation during the year | NPR/MEPJ |
Early follow-up by GP, respiratory diagnoses | Three categories: Contact with GP within 30 days after at least one COPD hospital admission; no or later follow-up only; no COPD hospital admissions during year | NPR/MEPJ |
Care interaction, respiratory diagnoses | Indicator of fees for interaction between either GP/specialist, GP/long-term care or GP/physiotherapist at least once during year | KUHR |
Home visits by GP or physiotherapist, respiratory diagnoses | Number of home visits by GP or physiotherapist performed during the year | KUHR |
Characteristics of the regular GP | ||
GP specialist | Indicator of GP being a specialist in general practice | RGPR |
GP group practice | Indicator of GP practicing in a location shared with other GPs | RGPR |
List length | Number of individuals on the GP’s patient list | RGPR |
Contact rate GP and contract specialist, respiratory diagnoses | Contract specialist contacts per year per listed patient in sample | KUHR/RGPR |
Contact rate GP and physiotherapist, respiratory diagnoses | Physiotherapist contacts per year per listed patient in sample | KUHR/RGPR |
Contact rate GP and outpatient hospital, respiratory diagnoses | Outpatient hospital contacts per year per listed patient in sample | NPR/RGPR |
Other health factors | ||
Comorbidities | Yearly indicators for each of 17 comorbidities commonly associated with COPD, see Table S1 for details | NPR/KUHR |
Need-score for assistance in daily living | Yearly sum score of items in the activities of daily living (ADL) checklist at start of follow-up year, assume score of 0 if not receiving any long-term care service | MEPJ |
Home nursing | Yearly indicator of receiving home nursing | MEPJ |
Nursing home | Yearly indicator of being in nursing home | MEPJ |
Death | Yearly death indicator yes/no to capture deteriorating health near end of life | Cause of Death Registry |
Socioeconomics and -demographics | ||
Updated yearly | Age and gross income | Statistics Norway |
Constant | Gender, marital status when entering sample, highest attained education, indicator of permanent disability pension prior to or during follow-up | Statistics Norway |
Statistical methods
Main descriptives | ||||
---|---|---|---|---|
No. of patients | 24,074 | |||
No. of person-years | 148,128 | |||
Follow-up years per patient, mean (SD) | 6.2 (3.0) | |||
Age at inclusion, mean (SD) | 65 (12) | |||
Females (n) | 47% (11,295) | |||
Number of comorbidities, mean (SD) | 4.0 (2.3) | |||
Receiving disability pension prior to or during follow-up (n) | 35% (8,533) | |||
Receiving home nursing during follow-up (n) | 28% (6,825) | |||
Admitted to nursing home during follow-up (n) | 6% (1,344) | |||
Dead within follow-up (n) | 27% (6,521) | |||
No. patients with at least one COPD hospital admission during follow-up | 8,829 | |||
No. person-years with at least one COPD hospital admission during follow-up | 58,193 | |||
Inpatient care | Total | % person-years with > 0 occurrences (n) | Mean per patient per year | 1st -3rd quartile |
COPD hospital admissions, total sample | 25,012 | 10.5% (15,497) | 0.2 | 0.0-0.2 |
-Among patients with COPD hospital admissions during follow-up only | 25,012 | 26.6% (15,497) | 0.6 | 0.1–0.6 |
Non-COPD hospital admissions | 80,601 | 27.8% (41,152) | 0.6 | 0.0-0.7 |
-Among patients with COPD hospital admissions during follow-up only | 42,670 | 34.8% (20,263) | 0.8 | 0.2-1.0 |
Readmissions: | ||||
No. of COPD index admissions used in analysis | 18,372 | |||
No outpatient respiratory care during year prior to index admission (n) | 11.1% (2,046) | |||
90-day COPD readmissions | 2,642 | 10.8% (2,095) of index admissions | 0.14 per admission | 0.0–0.0 per admission |
Outpatient care, respiratory diagnoses | Total | % person-years with > 0 occurrences (n) | Mean per patient per year | 1st -3rd quartile |
GP contacts | 485,121 | 67.3% (99,714) | 3.3 | 1.0-4.3 |
Emergency room contacts | 26,388 | 9.9% (14,636) | 0.1 | 0.0–0.0 |
Physiotherapy contacts | 292,104 | 6.6% (9,717) | 1.6 | 0.0–0.0 |
Contract specialist contacts | 42,679 | 13.6% (20,174) | 0.3 | 0.0-0.2 |
Outpatient hospital contacts | 64,709 | 17.2% (25,512) | 0.4 | 0.0-0.4 |
Rehabilitation | 12,297 | 2.2% (3,255) | 0.1 | 0.0–0.0 |
Outpatient care, non-respiratory diagnoses | ||||
GP contacts | 1,488,029 | 90.5% (134,066) | 10.4 | 4.3–13.7 |
Emergency room contacts | 67,217 | 19.4% (28,753) | 0.7 | 0.0-0.7 |
Physiotherapy contacts | 539,714 | 18.2% (26,964) | 0.2 | 0.0-0.1 |
Contract specialist contacts, | 196,774 | 42.2% (62,552) | 1.3 | 0.0-1.7 |
Outpatient hospital contacts | 371,300 | 54.6% (80,828) | 2.7 | 0.5–3.3 |
Rehabilitation | 35,111 | 7.4% (11,013) | 0.3 | 0.0-0.1 |
Care indicators | ||||
Continuity of GP care | N/A | N/A | 0.7 | 0.6–0.9 |
Spirometry performed at GP or contract specialist | 34,440 | 23.3% (34,440) | 0.2 | 0.0-0.4 |
Home visits by GP or physiotherapist | 21,972 | 6.2% (9,198) | 0.2 | 0.0-0.1 |
Care interaction fees | 32,503 | 9.2% (13,564) | 0.3 | 0.0-0.2 |
Results
Regression results, COPD hospital admissions
Regression results, 90-day COPD readmissions
Outcome: | Next-year COPD hospital admissions (n = 148,128) | 90-day readmissions (n = 18,372 index hospital admissions) |
---|---|---|
Independent variable: | IRR (95%-CI) | IRR (95%-CI) |
Care indicators | ||
Spirometry performed at GP or contract specialist | 0.93 (0.88–0.97)* | 1.04 (0.91–1.20) |
Continuity within GP care | 0.85 (0.79–0.91)* | 0.87 (0.74–1.04) |
Rehabilitation within 30 days vs. later after COPD hospital admission | 0.82 (0.70–0.95)* | 0.86 (0.70–1.07) |
No hospital admission/rehabilitation vs. rehabilitation after COPD hospital admission | 0.94 (0.82–1.07) | 0.43 (0.37–0.50)* |
Follow-up by GP within 30 days vs. no/later follow-up after COPD hospital admission | 0.92 (0.87–0.98)* | 1.09 (0.97–1.22) |
No hospital admissions vs. no/later follow-up by GP after COPD hospital admission | 0.45 (0.42–0.48)* | N/A |
Care interaction fees | 0.93 (0.86–0.99)* | 1.01 (0.87–1.16) |
Home visits by GP or physiotherapist | 1.00 (1.00-1.01) | 1.01 (1.00-1.02) |
Characteristics of the regular GP | ||
GP specialist | 0.99 (0.94–1.05) | 1.01 (0.87–1.15) |
GP group practice | 0.91 (0.81–1.03) | 1.05 (0.80–1.39) |
List length per 100 patients | 0.99 (0.98-1.00)* | 1.00 (0.98–1.01) |
Contact rate GP and contract specialist, respiratory diagnoses | 1.08 (1.03–1.13)* | 1.08 (0.99–1.19) |
Contact rate GP and physiotherapist, respiratory diagnoses | 1.00 (1.00–1.00) | 1.00 (0.99–1.01) |
Contact rate GP and outpatient hospital, respiratory diagnoses | 1.05 (0.99–1.11) | 1.01 (0.98–1.04) |
Comorbidities | ||
Alcoholism | 1.45 (1.31–1.60)* | 1.20 (0.94–1.52) |
Anemia | 0.95 (0.87–1.05) | 1.16 (0.96–1.40) |
Depression | 1.20 (1.12–1.28)* | 1.00 (0.87–1.15) |
Diabetes | 0.91 (0.85–0.98)* | 0.89 (0.75–1.05) |
Lung cancer | 1.09 (0.97–1.23) | 1.14 (0.90–1.44) |
Mental disorders | 1.02 (0.91–1.14) | 0.96 (0.72–1.27) |
Osteoporosis | 1.14 (1.05–1.22)* | 1.13 (0.96–1.34) |
Underweight | 1.03 (0.97–1.10) | 1.21 (1.03–1.42)* |
Socioeconomics | ||
Gross income (per 100,000 NOK) | 0.96 (0.93–0.99)* | 0.98 (0.94–1.02) |
Education: Secondary vs. primary | 0.89 (0.85–0.93)* | 0.96 (0.86–1.07) |
College/university vs. primary | 0.69 (0.63–0.74)* | 0.94 (0.79–1.13) |
Permanent disability pension | 1.36 (1.29–1.44)* | 1.02 (0.89–1.18) |