Chapter 9: Life with arthritis in Canada: a personal and public health challenge – Hospital services for arthritis

Chapter Nine: Hospital services for arthritis

Table of Contents

• Introduction
• Hospitalizations and day surgeries for arthritis
  • Hospitalizations for men and women
• Hip and knee replacements
  • Men and women
  • Joint replacement and obesity
  • Provincial/territorial variation
  • Length of stay in hospital
• Summary

Introduction

While the majority of individuals with arthritis receive care in ambulatory settings, many require diagnostic or therapeutic services in hospital and have same-day surgical procedures.^{Footnote 2} Admissions to hospital can be for either medical or surgical management of the disease.

Medical hospitalizations may be required to manage the non-joint related consequences of arthritis, arthritis-related pain and disability, or the side effects of drugs used to treat arthritis, such as gastrointestinal (GI) complications.

Orthopaedic surgery is the most common type of surgical intervention for individuals experiencing severe pain and joint damage when non-surgical treatments have had their maximum impact.^{Footnote 5} Surgical procedures for arthritis range from joint fusions to joint replacements. Joint replacement surgery has been shown to be a cost-effective procedure for reducing pain and improving physical function in individuals with advanced arthritis.^{Footnote 3} Joint replacements have been developed for various joints, however, the most frequently replaced joints are the hip and knee, followed by the shoulder.

This chapter focuses on hospital care provided to Canadian residents 15 years of age and older with arthritis, including hospitalizations (medical and surgical) and day surgeries. Data are also presented on total joint replacement surgeries. Information regarding wait times as well as readmissions and complications for total joint replacement are not included in this chapter however, have been published by the Canadian Institute for Health Information (CIHI).^{Footnote 7} Data for this chapter were obtained from several national databases maintained by CIHI for the fiscal years 2001/02 to 2005/06.

Hospitalizations with an arthritis diagnostic code were classified into five groups:

• inflammatory arthritis (e.g., rheumatoid arthritis (RA));
• osteoarthritis (OA);
• systemic connective tissue disorders (e.g., lupus);
• soft tissue disorders (e.g., rotator cuff syndromes, synovitis); and
• 'other arthritis' (e.g., spondylosis and allied disorders, internal joint derangement).

For comparative purposes, data on hospitalizations are also presented for non-arthritis diagnoses.

Hospitalizations and day surgeries for arthritis

In 2005-2006, there were 2.2 million hospitalizations for individuals aged 15 years and older in Canada, of which 1.5 million were for medical care and 721,000 were for surgery. Arthritis was associated with over 5.9% (129,205) of the total hospitalizations, but accounted for more of the surgical hospitalizations – 91,556 or 12.7% of the surgical hospitalizations. Medical hospitalizations included 37,649 (2.6%) with arthritis as the most responsible diagnosis. Of all arthritis hospitalizations, surgical hospitalizations (71%) were more common than medical ones. This is in contrast to non-arthritis conditions where surgical hospitalizations were less common (32% of all non- arthritis hospitalizations).

The number of hospitalizations for arthritis conditions were relatively stable between 2001/02 and 2004/05 with a minor increase in 2005/06, while non-arthritis conditions remained relatively stable during this time period (Figure 9-1). While the age- and sex-standardized rate of hospitalizations for arthritis conditions decreased between 2001/02 and 2004/05 and increased slightly between 2004/05 and 2005/06, the rate of hospitalizations for non-arthritis conditions decreased during this period of time.

The number of hospitalizations can remain stable while rates go down, as the two populations (those with arthritis and those without) have different age and sex compositions. Therefore standardized rates were calculated to identify if the differences remained after adjusting for these differences.

Between 2001/02 and 2005/06, the age-standardized rates for medical and day surgery hospitalizations for arthritis decreased (Figure 9-2).

The rates of surgical in-patient hospitalizations for arthritis increased during the same time period. This increase, particularly in 2005/06, may be related to initiatives to decrease wait times for procedures in priority areas such as hip and knee replacement surgeries.^{Footnote 4}

Among the five types of arthritis, medical hospitalizations rates were higher for the more common soft tissue disorders (e.g., synovitis and bursitis), inflammatory arthritis and 'other arthritis' (e.g., internal joint deran- gements) than for OA or systemic connective tissue disorders (e.g., lupus) (Figure 9-3). Medical hospitalization rates decreased after 2001/02, with the exception of the soft tissue disorders, which showed a slight increase in 2005/06.

Between 2001/02 and 2005/06, surgical hospitalizations for all types of arthritis remained stable with the exception of OA whose rate increased particularly between 2004/05 and 2005/06 (Figure 9-3). As noted above, this is likely related to the implementation of several initiatives to decrease wait times for total hip and knee replacements used to treat OA in late 2004/05.

Day surgeries, most often arthroscopic surgical procedures, were more common for individuals with 'other arthritis', likely related to injury of the joint (e.g., joint derangement of the knee), soft tissue disorders and OA (Figure 9-3).

^{Footnote 8} The rate of day surgeries decreased between 2001/02 and 2003/04 for most of the diagnostic groups and then levelled off thereafter.

Overall, OA accounted for most of the hospitalizations related to arthritis, particularly surgical hospitalizations. Consistent with the high frequency of OA, knee and hip replacement surgeries were also common, accounting for over 60% of surgical hospitalizations related to arthritis. Similar findings have been reported in the United States.^{Footnote 9} Inflammatory types of arthritis accounted for about one in four of all arthritis-related medical hospitalizations, likely due to complications of the disease.

Hospitalizations for men and women

The rate of medical hospitalization increased with age and was more than twice as high in the 75 and over age group than in the 65 to 74 year old age group (Figure 9-4). The rate of surgical hospitalizations increased to age 65 to 74 then decreased for both men and women. The rate of day surgeries peaked in the 55 to 64 year old age group for both men and women and then declined. These findings could indicate that other management approaches are used in the oldest age group due to the increased risk of complications associated with surgery in this age group.

The rate of surgical hospitalizations was higher than the rate of medical hospitalizations for men and women in every age group (Figure 9-4). In general, the rate of hospitalizations was slightly higher for women than men, with the exception of day surgeries. Young men (aged 15-44 years) had higher day surgery rates than young women. This may be related to higher rates of joint injury among young men.

The highest proportion of all arthritis-related hospitalizations was attributed to OA for men and women in all age groups, with the exception of those between 15 and 44 years of age (Figure 9-5). In contrast, the proportion attributed to soft tissue disorders or 'other arthritis' was higher in men and women under 45 years of age.

Hip and knee replacements

In 2005-2006, 59,200 joint replacements for arthritis were performed in Canada. Nearly all of these (57,300) were hip or knee replacements (Figure 9-6). In each year between 2001/02 and 2005/06, the number of knee replacements exceeded the number of hip replacements, and this gap widened over time (Figure 9-6). The number of knee replacements increased by 59% and the number of hip replacements increased by 47%. After adjusting for the older age group who have hip replacements and the aging of the population over that time period, knee replacements still increased 1.3 times more than hip replacements. The observed increases may be explained by the investments in Patient Wait Time Guarantees towards reducing the wait times for hip and knee replacements together with an increasing number of people with arthritis.

Men and women

The number of joint replacement procedures increased in every age group between 2001/02 and 2005/06 (Figure 9-7). This finding highlights the fact that more Canadians are getting joint replacements even within the younger age groups. A similar situation has been recently reported in the US.^{Footnote 10} This may put additional pressure on the healthcare system, since younger individuals are likely going to require a revision surgery (i.e., a procedure to replace a worn out hip or knee implant) in the future.

Number of arthritis-related hip and knee replacements, by age, Canada, 2001/02–2005/06

The rate of hip replacements in Canada increased with age in 2005-2006, peaking among both men and women aged 65–74 years (Figure 9-8). Similarly, the rate of knee replacements increased with age in 2005- 2006, peaking among women aged 65–74 years and among men over 75 years of age (Figure 9-9). The majority of these surgeries were for the management of OA. The Canadian Joint Replacement Registry (CJRR) demonstrated that OA accounted for over 83% of hip replacements and over 93% of knee replacements in Canada in 2005/06.^{Footnote 6} Adults aged 65 years and older had the largest number of hip and knee replacements, reflecting the aging of the Canadian population.

Joint replacement and obesity

Obesity is an important factor in the development of OA, particularly OA of the knee, and for individuals who are obese in early adulthood.^{Footnote 3} Obesity has also been found to be associated with the need for total hip and knee replacements.^{Footnote 14}

The Canadian Joint Replacement Registry (CJRR) contains information from surgeons on weight and height of individuals undergoing hip and knee replacement. Data in this section are taken from the 2007 CJRR report.^{Footnote 6}

In 2005-2006, 74% of those who underwent hip replacement and 87% of those who underwent knee replacement were overweight or obese (Figure 9-10).

Given that the prevalence of obesity has increased in Canada in recent decades, it is anticipated that the number of overweight/ obese individuals needing total joint replacements will continue to increase^{Footnote 15} Health promotion programs for reducing overweight and obesity in the population are critical to counter this trend.

More men than women who had a hip or knee replacement were overweight or obese (85% and 80%, respectively). The proportion of individuals that were obese was higher among those undergoing knee replacement compared to those having a hip replacement among men and women, in all age groups (Figures 9-11 and 9-12).

A large proportion of individuals who were obese and who had either knee or hip replacements were of working age i.e., less than 65 years old (66% and 44%, respectively). Knee and hip replacements occurred at an earlier age for those individuals who were overweight or obese whereas, they occurred at an older age for those of normal or underweight. These results suggest that obesity is likely to contribute to an earlier need for joint replacement.

Text Equivalent - Figure 9-11

Provincial/territorial variation

Rates of hip and knee replacements varied considerably by province in 2001/02 and 2005/06 (Table 9-1). Rates in Quebec and Newfoundland and Labrador were the lowest among all jurisdictions. With the exception of the Territories, the hip and knee replacement rates increased in all provinces between 2001/02 and 2005/06.

Length of stay in hospital

The average length of stay for individuals with hip replacements was slightly longer than for those with knee replacements. For hip replacements in 2005-2006, the average length of stay for women was higher than for men; no sex difference was observed for knee replacements (Figure 9-13) Between 2000/01 and 2005/06, the average length of stay for hip replacements declined from 10 to 8 days and from 8 to 6 days for knee replacements (Figure 9-14). These findings may partially reflect the inclusion of emergency surgery for hip fractures (approximately 5% of all total hip replacement)in this analysis.Footnote 6

Summary

• In 2005-2006, there were 2.2 million hospitalizations in Canada; of these, 132,000 (6%) were associated with arthritis.
• Arthritis accounted for 3% of the 1.5 million medical hospitalizations (45,000 hospitalizations annually) and 13% of the 721,000 surgical hospitalizations (93,730 hospitalizations annually).
• Osteoarthritis accounted for most of the hospitalizations related to arthritis, particularly surgical hospitalizations related to joint replacements.
• The rate of hospitalizations for arthritis in Canada increased between 2001/02 and 2005/06, while hospitalization rates for non-arthritis conditions decreased. This was due in part to an increase in surgical hospitalizations for joint replacements.
• The total number of joint replacements increased by 54% between 2001/02 and 2005/06. Adults aged 65 years and older had the largest number of hip and knee replacements.
• In 2005-2006, 74% of individuals who underwent hip replacement and 87% of those who received knee replacements were overweight or obese.
• A large proportion of individuals who were obese and who had either hip or knee replacements (66% and 44% respectively) were of working age i.e., less than 65 years old.
• Given the current high and increasing prevalence of overweight and obesity in the population, it is expected that the number of individuals needing total joint replacements will continue to increase.