Predictors of inpatient rehabilitation after total knee replacement: an analysis of private hospital claims data

In reply: We welcome the debate about the choice of rehabilitation at home as an effective treatment option. Our study1 supports the position statement of the Rehabilitation Medicine Society of Australia and New Zealand (RMSANZ)2 and the comments of the Australasian Faculty of Rehabilitation Medicine of the Royal Australasian College of Physicians which recommend inpatient rehabilitation be based on patient need. We considered many clinically relevant patient factors identified in the position statement, including age, socio‐economic status, comorbidities, living alone and surgical complications.1,2 Large interhospital variation in inpatient rehabilitation persisted after adjustment for these factors. It seems implausible, given the large sample, that unobserved patient factors could explain the wide variation (76% in one large volume private hospital, 10% in another1), but we acknowledge our study could be improved with function and obesity measures in particular.

Same day inpatient rehabilitation was not classified as inpatient rehabilitation. The average inpatient rehabilitation stay in our study was 11 days.1 The saving estimate was not based on the previous year's private hospital claims. It represents the potential savings if inpatient rates were reduced from 45% to 31% using a cost differential from a recent Australian study.3 We maintain it is relevant to highlight where other jurisdictions have achieved similar outcomes across settings. However, we note these samples are often biased to uncomplicated patients.

The work of the Australasian Rehabilitation Outcomes Centre (AROC) is commended for supporting quality collection and reporting of rehabilitation outcomes. Our article referred to a lack of corresponding data across settings1 — functional independence measure for inpatients and the Lawton Scale for ambulatory patients.4 We support AROC expanding outcome‐reporting for ambulatory care. The use of consistent measures across settings would yield additional insights into low value care. While clinicians rightly focus on patient outcomes, from a system perspective, ignoring cost is not sustainable.

We look forward to all stakeholders working together to advocate for best practice.