Background/Purpose: Length of Stay (LoS) is one of the main drivers of costs for orthopedic surgery in RA.  Better medical and surgical treatments in recent years should result in shorter LoS. Studies have reported LoS trends in RA-related orthopedic interventions, but less is known about clinical factors affecting it.  In the current economic climate, with over-pressurized health services, identifying and targeting such factors could result in reduced LoS, and improved health care utilization planning. Methods: LoS has been examined in two very similar multi centre inception cohorts, the Early RA Study (ERAS) (n=1465, 1986-1999) and the Early RA Network (ERAN) (n=1236, 2002-2010). Details of orthopedic interventions included date, type of procedure and LoS. The results were validated against the National Joint Registry and Hospital Episode Statistics, and follow up based on the National Death Register. Standard clinical, laboratory and x-ray measures recorded at baseline and annually were used to investigate factors affecting LoS with univariate and multivariate regression analysis. Results: There were 770 (29%) out of 2701 patients in ERAS & ERAN who had a total of 1602 procedures:  40% major, of which 88% were total joint replacements (mainly knee followed by hip); 24% were intermediate (mainly hand/foot surgery) & 16% were minor (soft tissue surgery surgery/tendon transfers). A gradual reduction in the median LoS was noted over 25 years for major, intermediate and minor procedures: 10, 4 & 2 days respectively (IQRs 7-15, 3-7, 1-4) in ERAS & 7, 3 & 1 days (IQRs 5-8, 1-7, 1-2) in ERAN.  Figure 1 shows the changing median LOS for the commonest types of surgery: Total Knee & Hip Replacements (TKRs & THRs) over 25 years. Figure 2 shows TKR median LoS compared with national data. Extrapolation of national data suggests that in the 1990s TKRs resulted in longer LoS than in the 2000s. The cost of a TKR based on 5 days LoS currently in the UK is £5576. The decline in LoS across various procedures has resulted in reduced costs. In multivariate analyses LoS varied significantly by type of procedure, DAS, hemoglobin (HB) levels and HAQ scores. Normal baseline HB significantly reduced LoS by 1.8 days (p=0.001), baseline HAQ<1 by 1.8 days (p=0.002) & low 1year DAS (<3.2) by 1.1 days (p=0.051). Conclusion: LoS in RA-related orthopedic surgery has declined over the last 25 years, which could be a reflection of improved management of RA, and medical and surgical in patient treatments.  Normal baseline HB, low baseline HAQ and low DAS at 1 year were found to be significant predictors for LoS.

Figure 1.

Figure 2