Table 1 Baseline characteristics of the studies included

Andersen 2009 [35]

Denmark

Linkage of National patient register (LPR) and Health Insurance Register (SSR)

2006

102

3

Inclusion:

- All patients undergoing acute or elective primary TKA surgery regardless of age

Exclusion:

- Length of stay in hospital ≥20 days

70.2 (62.0%)

Hamilton 2019 [36]

United Kingdom

Self-reported questionnaire

01/2013 to 09/2015

1374 (THA = 1395)

1

Inclusion:

- All patients undergoing unilateral primary TKA and THA regardless of age

Exclusion:

- Not reported

69.7 (56.6%)

Han 2015 [37]

Australia

Study-specific diary during the 6-week, post-discharge period

09/2009 to 10/2012

196

10

Inclusion:

- All patients between 45 and 75 years undergoing elective/planned unilateral or bilateral primary TKA

- Eligibility for being discharged into home environment

Exclusion:

- Previous unicompartmental arthroplasty/surgery of the same knee within the last 12 months

- Comorbidity precluding exercise at 50–60% maximum heart rate, rheumatoid arthritis or major neurologic conditions

65.4 (53.0%)

Smith 2020 [38]

United Kingdom

Linkage of self-reported questionnaire and NJR

12 months between 2009 and 2010

20,260 (THA = 17,338)

Not reported

Inclusion:

- All patients undergoing primary TKA or THA

performed in England

Exclusion:

- Patients not registered in NJR and not part of NJR longitudinal PROMs programme

69.1^a (56.3%)^a

Warren 2018 [39]

United States

Linkage of Centres from Medicare & Medicaid Services (CMS) and Health Resources and Services Administration’s (HRSA) Area Health Resource File (AHRF)

07/2010 to 06/2011

3482

2664

Inclusion:

-All patients undergoing TKA (DRG codes 469, 470 and surgical procedure code 81.54)

Exclusion:

- Patients discharged to hospice, long-term care, or a psychiatric hospital or transferred to another acute care hospital

- Patients who left against medical advice

71.3 (59.2%)