5.6.3. Data description and analysis
The major musculoskeletal problems and conditions and
their impact are described in the following section in terms of definitions,
incidence and prevalence; determinants; disability and quality of life; health
care utilization; economic impact and future trends. Estimates of incidence and prevalence for the major
musculoskeletal conditions and problems for a Caucasian European population
derived from studies in Europe and North America (Symmons, 2003) are given in
table 5.6.1.
Table 5.6.1. General
Incidence and Prevalence Rates
Musculoskeletal Pain and Disability
Definitions
Musculoskeletal pain is experienced by most people at some
time.
Musculoskeletal pain may be associated to a specific
musculoskeletal condition or be a regional or generalized pain problem. It can
be acute and transient, such as following injury; recurrent as is often the
situation with low back pain; or may be chronic as is usually the situation
with osteoarthritis and rheumatoid arthritis.
Prevalence
In Europe, just over one-fifth (22%) of the
population currently has, or has experienced long-term muscle, bone and joint
problems such as rheumatism and arthritis (Eurobarometer Special Report No
272e, 2007). A survey in Norway found that only 15% of 20-72 year-olds reported
no pain during the previous year, whereas 58% reported musculoskeletal pain
during the previous week and 15% had musculoskeletal pain every day during the
previous year ( Natvig et al, 1995). They were the most common self-reported
chronic sickness in men and women from 16 to 74 years of age in the UK General Household Survey 2002 (Office
for National Statistics UK, 2002)
and almost as common as cardiovascular conditions in those over 75.
The prevalence of musculoskeletal pain increases mainly up
to about 65 years of age (Andersson et al, 1993; Bergman et al, 2001; Hagen et
al, 1997) (Figure 5.6.1), explained partly by a cumulative effect of chronic
musculoskeletal conditions, which become more prevalent with older age (Figure
5.6.2). A decline in the complaint of pain has been noticed over 65 years of
age; a plausible explanation for this could be the decline around the age of
retirement of the adverse physical and mental effects of the working place.
Figure 5.6.1. The age and
sex-specific prevalence of chronic musculoskeletal pain (95% Cl) among all
respondents (n=2755) in Sweden
Figure 5.6.2. Prevalence of self
reported musculoskeletal diseases per age group in the Netherlands
Figure 5.6.2.b Prevalence of self
reported musculoskeletal diseases per age group in the Netherlands (different
group of diseases)
Disability and quality of life
Musculoskeletal conditions are associated with the poorest
quality of life if compared to other chronic conditions (Sprangers et al,
2000), in particular related to physical functioning, role functioning and
pain.
Musculoskeletal conditions are the leading
cause of disability for both men and women, as well as for the whole population
and the elderly (Picavet and van den Bos, 1997). Musculoskeletal pain is
usually associated to limitations of activities and restricted participation
(European Commission (2004): European Action Towards Better Musculoskeletal
Health), which is greater with more widespread pain, back pain and knee pain
(Urwin et al, 1998). In the Eurobarometer Survey just under a third (32%) of
all respondents said that in the week preceding their interview they
experienced muscle, joint, neck or back pain which affected their daily
activities and a quarter of all EU respondents say that at some point in their
life they have experienced chronic restrictive musculoskeletal pain
(Eurobarometer Special Report No 272e, 2007).
The prevalence of physical disabilities due to a
musculoskeletal condition has repeatedly been estimated to be 4-5% of the adult
population (Reynolds et al, 1992). The prevalence is higher in women, and
increases strongly with age.
In the UK, a report on disabled adults from the Office of
Population Census and Surveys, found that 30% of disabled people had arthritis
(Office for
National Statistics, 1989).
A large population study, The Calderdale study (Badley and
Tennant, 1993), which utilised a clinical validation of rheumatic diagnosis and
disability, found that 24% of the whole population reported some joint
problems. Of those adults with a rheumatic disorder, 8.2% were disabled and of
these approximately 5% reported arthritis, mainly osteoarthritis, as the cause.
Musculoskeletal conditions are a major cause of disability
adjusted life years (DALYs) and years lived with disability (YLDs). They are
seldom fatal and the level of disability for many is low to moderate.
Musculoskeletal conditions rank in the top 10 causes of DALY in Europe (WHO European Strategy for NCD 2006) and osteoarthritis is the 5th greatest cause of
YLDs in high-income countries (Lopez et al, 2006).
Health care utilization
Musculoskeletal problems are a very common reason for
primary care consultation even though 20-39% of people with musculoskeletal
problems do not consult a primary care physician (Lock et al, 1999; Woolf et
al, 2004). Musculoskeletal conditions are major reason for patients to seek
expert referral for (Lin et al, 2000), see physiotherapists and complementary
therapists and use alternative medications or supplements. Over three quarters
of patients presenting to practitioners of the major complementary disciplines
have a musculoskeletal problem as their main complaint (Zollman and Vickers,
1999).
In the Swedish Cost of Illness Study, musculoskeletal
conditions were the most expensive disease categories representing 22.6% of the
total cost of illness (Jacobson and Lindgren, 1996).
Economic impact
Musculoskeletal problems are the most common cause of
health problems limiting work in developed countries, with up to 60% of people
on early retirement or long-term sick leave claiming them
as the reason (Swedish Yearbook of Health and Medical Care, 2001).
In the Netherlands, musculoskeletal conditions ranked
second as a health care cost in 1994 (Meerding et al, 1998), accounting for 6%
of total health care costs compared to 8.1% for mental retardation. Coronary
heart diseases and other circulatory diseases accounted for 4.8%. This study
only considered medical costs. The inclusion of indirect costs, such as
informal care would have greatly increased the costs related musculoskeletal
diseases as studies have shown that for osteoporosis and arthritis the
healthcare costs only represent between a quarter and a third of the total
costs. The costs were considerable at all ages, ranking fifth at 15 – 44,
second at 45 – 64 and third at age 65 – 84 after dementia and stroke.
Osteoarthritis
Definition
Osteoarthritis (OA) is characterised by focal areas of
loss of articular cartilage within synovial joints, associated with hypertrophy
of bone (osteophytes and subchondral bone sclerosis) and thickening of the
capsule. OA can affect any joint, but is most common in the hand, spine, knee,
foot and hip. This pathological change, when severe, results in radiological
changes (loss of joint space, sclerosis and osteophytes) that have been used in
epidemiological studies to estimate the prevalence of OA in different joint
sites (Kellgren and Lawrence, 1958). Clinically, the condition is characterized
by joint pain, tenderness, limitation of movement, crepitus, occasional
effusion and variable degrees of local inflammation.
Case definition can be based on pathological changes seen
on x-rays, by the presence of joint symptoms or require both. It can also be
related to the affected joints. The preferred definition for OA includes both
x-ray findings and the presence of joint pain most days (Altman et al, 1986).
Natural history
The course of the disease varies but is often progressive
with radiographic changes slowly deteriorating in the hands (Kallman et al,
1990), knees (Dougados et al,
1992), and hips (Danielsson,
1964), leading to increased pain and disability (Dougados et al, 1992). Progression of OA is accelerated by age,
and in the hip and knee by obesity and intensive physical
activity (Table 5.6.4). The pain and disability associated with OA
increases with progressive joint damage.
Incidence
The incidence of osteoarthritis is problematic to estimate
and there are little data because of its gradual progressive development and
difficulties in the definition of a new case. It can be estimated by the number
presenting to health care with OA by agreed criteria. An estimation of the
incidence of severe osteoarthritis may be obtained from the figures of the
progression of radiological osteoarthritis from a low to a higher radiological
score, with or without the onset of clinical symptoms. Data is not available
for all EU countries. However, major differences in the epidemiology of risk
factors, such as obesity, may result in inter-country variation.
The incidence and rate of progression increases with age.
Prevalence
Prevalence measured using radiological criteria alone can
lead to overestimates of the burden of disease as radiological changes are not
always accompanied by symptoms. The presence of knee pain without an
examination or radiograph to confirm causation will also lead to an
overestimate of prevalence. Likewise, surveys that ask for self-reported
chronic conditions including osteoarthritis over-estimate the prevalence
(Symmons et al, 2003). For example, a study of women aged 45-65 in the UK showed that the prevalence of symptomatic knee OA was 2.3% compared to 17% based on
radiologically defined knee OA (Spector et al, 1991).
The prevalence of OA increases indefinitely with age as
OA is not reversible (Figures 5.6.3 and 5.6.4 and Tables 5.6.1-5.6.3) and this
is where the burden lies. Surveys show that osteoarthritis changes are uncommon
in those under the age of 40 but are seen in most over the age of 70 (van Saase et al, 1989). For example, in people aged 55 – 74 the
prevalence of OA of the hand is 70%, foot OA 40%, knee OA 10% and hip OA 3%
(Lawrence et al, 1998).
Men are affected more often than women among those aged
<45, whereas women are affected more frequently among those aged >55
(Petersson and Jacobsson, 2002). There are insufficient data to know if there
is any geographical variation in prevalence.
In many people there will be several joints involved
and it is estimated in the Global Burden of Disease study that approximately
10% of the population 60 years old or older have symptomatic problems that can
be attributed to OA (Symmons et al, 2003).
Table 5.6.2. Osteoarthritis
Incidence in selected European countries
Table 5.6.3. Osteoarthritis
Prevalence in selected EUGLOREH Countries
Table 5.6.4. Osteoarthritis
Prevalence (Radiographic Criteria) in selected European Countries
Figure 5.6.3. Prevalence of knee OA
in Europe
Figure 5.6.4a. Prevalence of radiographic OA by age A) Men
Figure 5.6.4b. Prevalence of radiographic OA by age B) Women
Determinants, risk factors and population at risk
Age is the strongest predictor of the
development and progression of radiographic OA (Table 5.6.4). Almost everyone
who reaches 90 years of age will have OA in some joint (Petersson and Jacobsson, 2002).
OA is more common in females, increasing at
the age of 50 especially in the hand and knee. The role of the menopause is
unclear but hormone replacement therapy (HRT) is associated with a reduced risk
of the development and progression of knee OA (Petersson and Jacobsson, 2002).
Obesity (BMI) is a risk factor for the
development of OA of the hand, knee and hip and for progression in the knee and
hip (Woolf, 2007). One study showed obesity to result in an odds ratio of about
8.0 for developing OA knee (Davis et al, 1990). It is estimated that a decrease
of 2 BMI units would decrease the risk of developing knee OA by 20-30% (Felson,
1996).
Trauma, particularly in men, is associated
with development of knee OA. Other mechanical factors and intensive activity are risk
factors for the development of OA of the knee and hip shown by associations
with malalignment, repeated knee bends or squatting, intensive sports
activities and certain physically demanding occupations (Petersson and
Jacobsson, 2002).
Farming presents the greatest relative risk
for OA: 4.5 for farming 1-9 years and 9.3 for farming ten years or more when
compared to sedentary occupations (Croft et al, 1992).
There is a negative association between
osteoarthritis and smoking (Felson et al, 1996).
These risk factors are summarised in table
5.6.5.
Table 5.6.5. Risk factors for
incidence and progression of osteoarthritis of the knees, hips, and hands.
Impact
Osteoarthritis of the hip, knee and hand are the most
important from the point of view of public health, based on their prevalence
and associated disability. Osteoarthritis results in pain, loss of motion of
affected joints, which limits related activities such as manual dexterity and
mobility. Osteoarthritis of the knee is a major cause of mobility impairment,
particularly among females.
OA was estimated to be the 5th leading cause of non-fatal
burden of disease in high income countries in 2001 measured as healthy life
lost as a result of disability (Global burden and risk factors 2006) .
Economic impact is a consequence of work loss, and of
social and health care. There is little data available specifically for OA.
However in Sweden, osteoarthritis was estimated to incur SEK 7.4 billion (Euro
690 million) in 1994, of which SEK739 million (Euro 59.6 million) was for
inpatient care and SEK 6.4 billion (Euro 630.4 million) for productivity
losses (Jonsson and Husberg, 2000). In France estimates of the costs of
osteoarthritis from national data were 0.1% of 1991 GNP, of which almost
two-thirds were direct costs of medical care (Levy et al, 1993). OA is a major
cause of chronic pain and disability resulting in analgesic and NSAID usage,
and rehabilitation. Joint replacement is a major cost. Total hip replacement
rates, usually for OA, vary in OECD countries between 50 and 140 procedures /
100,000 (Merx et al, 2003). The estimated requirement for knee replacement is
27.4 joints per 1000 people aged 35 or more according to severity of knee
disease (Juni et al, 2003).
Future trends
Future changes in the incidence and prevalence of OA are
difficult to predict. As incidence and prevalence rise with increasing age and
obesity, extending life expectancy will result in greater numbers with OA and
greater disability. The burden however may be controlled by joint replacement
surgery although the costs of this will be considerable and strategies for
prevention are central to controlling the burden.
Rheumatoid arthritis
Definition
Rheumatoid arthritis (RA) is an inflammatory
condition that predominantly affects synovial joints. It is the most common
form of chronic polyarthritis. The established disease is distinguished from
other forms of arthritis by various criteria, with ACR as the preferred
criteria (Arnett et al, 1988).
However, it
is difficult at onset to distinguish inflammatory polyarthritis that will
persist and develop the features of rheumatoid arthritis from that which will
resolve or progress into another form of chronic arthritis. At present, there
is much research trying to solve this issue and identify rheumatoid arthritis
at the earliest stage to allow early treatment. Recently, recommendations have
been made for early diagnosis inclusive of the anti-cyclic citrullinated
peptide antibodies marker (Combe et al, 2007).
Natural history
Inflammatory polyarthritis has a remission rate of 30-40%
in inception cohort studies, whilst there is little evidence of persistent
disease in population studies in 75% of people after 5 years. However the
remission in those classified as already having RA at presentation is lower,
namely around 10-30%. Clinic-based established cases have a far worse prognosis
and until the 1980’s most had significant progression over 10 years with few
being controlled on symptomatic therapy alone. Spontaneous remission rates are
only 5-7% with a median duration of 10 months. There is also an increased
mortality associated with RA (EULAR Online Course, 2008).
Modern treatment is effective in controlling disease
activity and reducing long-term disability. Early treatment aimed at
controlling disease activity is the present strategy to prevent this disability
(European Commission (2004): European Action Towards Better Musculoskeletal
Health).
Incidence
A review of European studies using the 1987 ACR criteria
(European Commission (2003): Indicators for Monitoring Musculoskeletal Problems
and Conditions) gives estimates of the annual incidence of RA range from 4–13
per 100,000 for adult males and 13-36 per 100,000 for adult females. Estimates
of the prevalence of RA range from 1-6 per 1000 for men and 3-12 per 1000 for
women. In all studies the prevalence is higher in women than men (the ratio
varied from 1.7 to 4.0) .
The incidence of RA in women appears to have fallen
between the 1960s and 1980s and has stabilised since 1980s. This fall is now
reflected in recent prevalence figures for RA from the UK which show that, since the 1960s, there has been an approximate 25% fall in prevalence
in women aged 16-74.
The incidence and prevalence of RA generally rises with
increasing age until about the age of 70, to then decline (Linos et al, 1980). (Table 5.6.6)
Table 5.6.6. Prevalence and
incidence of rheumatoid arthritis from individual studies across Europe.
Prevalence
For both men and women there appears to be a gradient in
the prevalence of RA going from South (lowest) to North (highest). For example
the prevalence of RA in men in Finland is reported as 0.6%, France 0.32% and Italy 0.13%. In women, the prevalence in the same three countries is 1%, 0.86% and
0.51%. These figures are not directly comparable because they are not age
standardised; nevertheless, the pattern seems clear.
Determinants, risk factors and the population at risk
RA tends to run in families. One of the genetic components
of seropositive RA has been mapped to a short gene sequence now known as the
shared epitope. This appears to be the marker for RA disease severity rather
than susceptibility (Weyand et al, 1992).
Little is known about the environmental triggers for RA.
Infection may play a part in some individuals. There are complex interactions
between the female sex hormones and RA. The onset of RA is rare during
pregnancy and RA is more common in nulliparous women. The oral contraceptive
pill, or some other factor associated with its use, apparently protect against
the development of the severe RA. Again the frequency of the pill use,
nulliparity and breast-feeding varies considerably between communities and may influence
the epidemiology of RA. Smoking and obesity are also risk factors for RA
(Symmons and Harrison, 2000).
Base line predictors of future functional disability in
patients with early RA that have been identified in various cohorts include
older age, female gender, longer disease duration at presentation, presence of
rheumatoid factor, more tender and / or swollen joints and poorer function
(Ollier et al, 2001).
Base line predictors of future radiological change in
patients with early RA that have been identified in various cohorts include
older age, female gender, longer disease duration at presentation, presence of
rheumatoid factor and more tender and/or swollen joints (Ollier et al, 2001).
Impact
RA can be a severely disabling disease, but its impact is
changing due to advances in the management and use of different therapeutic
strategies. However, most data available are with less aggressive approaches
towards treatment with less effective therapeutic agents than those currently
used.
Hakala et al (Hakala et al, 1994) examined the severity of
RA in a population study using 1987 ARA criteria and found that about
two-thirds of cases had mild or moderate disability due to RA and less than 10%
had severe disability. The disability starts early and rises in a linear
fashion (Hochberg et al, 1992). Within ten years of onset, at least 50% of
patients were unable to hold down a full-time job in older studies (Brooks,
1997) but outcomes have improved over recent years with new disease modifying
drugs, better pain management and joint replacement surgery.
Although there is no cure for RA, long term disability can
be reduced with current therapies. Modern treatment is effective at controlling
disease activity and reducing long-term disability, whilst early treatment
aimed at controlling disease activity is the present strategy to prevent this
disability (European Commission (2004): European Action Towards Better
Musculoskeletal Health). Physiotherapy and adaptations to the home may also
reduce disability. It has been recently estimated that, with current management
applied optimally, the burden of disability due to RA might be further reduced
by 25% in developed countries.
Co-morbidities and mortality
RA is associated to reduced life expectancy. Mortality is
generally greater in studies reporting patients in the clinic setting who
usually suffer from a more severe form of the disease. Mortality is related to
severity of RA as expressed by functional status, health status and health
status perception, radiological damage and extra-articular manifestations (Naz
and Symmons, 2007). Co-morbidity, especially cardiovascular disease and
hypertension; formal education; socio-economic and marital status, but not
race, may also affect survival.
Economic impact
The direct and indirect cost of illness are twice as high
in people with RA compared to controls (Birnbaum et al, 2000). The direct costs
are typically between 25 and 50% of the total (Woolf, 2008). Direct costs are
high during the first 2 years, largely related to consultations; then they fall
and then gradually increase over the subsequent years due to the costs of
devices, adaptations and arthroplasty which contribute to 40% of the total
costs after 10 years (Hulsemann et al, 2005). These costs are strongly
influenced by inpatient care and admission rates which vary within and between
countries. The costs of medication have been found to be less than 20% of
direct costs in earlier studies but this has increased considerably with the
widespread use of anti-TNF (Woolf, 2008).
Future trends
Future changes in the incidence and prevalence of RA are
difficult to predict. Recent studies indicate a decline in its prevalence,
particularly among women (Spector et al, 1993). On the other side, RA is
expected to increase in the next 10 years in Europe due to the ageing
populations. The net result of these opposite trends, however, is unpredictable
and prospective figures should be collected through specific studies.
Osteoporosis and low trauma fractures
Definition
Osteoporosis is defined as a systemic skeletal disease
characterized by a low bone mass and a microarchitectural deterioration of bone
tissue, with a consequent increase in bone fragility and susceptibility to
fracture. In 1994 a WHO expert panel (WHO Technical Report No 843, 1994)
operationalized this concept by defining diagnostic criteria for osteoporosis
on the basis of measurement of bone mineral density (BMD). The risk of fracture
rises when the bone mineral density (BMD) declines, and the WHO operationalized
this concept by considering osteoporosis to be present when the BMD level in
women was 2.5 standard deviations or more below the normal mean for young
women.
The International Osteoporosis Foundation has recommended
that, for the purposes of diagnosis as opposed to those of assessment, BMD
should be measured at the hip using dual-energy X-ray absorptiometry. This
brought to the following values:
Osteoporosis: a BMD value at least
2.5 standard deviations below the mean BMD of young adult women (BMD T‑score
≤ –2.5).
Osteopenia (low bone mass): a BMD value between 1 and
2.5 standard deviations below the mean BMD of young adult women (–2.5 <BMD T‑score <–1).
Clinically, osteoporosis is recognized by the occurrence
of characteristic low-trauma fractures, the best documented of these being hip,
vertebral and distal forearm fractures.
Natural history
A classical case of osteoporosis may be present in a woman
about 55 years of age with a wrist fracture. Ten years later she may present
back pain, with or without minor trauma, and thoracolumbar spine X-rays may
show a vertebral fracture. She might have one of several risk factors: low body
weight, premature menopause, a family history of fractures, smoking,
heavy alcohol consumption, inactivity, calcium or vitamin D deficiency or
corticosteroid use. The back pain may remit and relapse with subsequent
vertebral fractures. Approximately 10–15 years later, at the age of 75–80, she
may fall and sustain a hip fracture, resulting in hospitalisation, a 20% excess
risk of death, considerable functional impairment and possibly a loss of
independence if she survives. Although this scenario is instantly recognizable,
osteoporosis may present any of a wide range of fractures and at a variety of
ages; it is also increasingly recognized among men.
Incidence
The incidence of osteoporosis is best measured indirectly
as the incidence of fractures resulting from the condition. The lifetime risk
or the 10 year probability of fracture can also be considered (van Staa et al,
2001). The lifetime risk of fragility fractures at the age of 50 or more is
considerable (Table 5.6.7).
Table 5.6.7. Estimated lifetime
risks of fractures in the UK at various ages
In Western populations the incidence of hip fractures strongly increases with
age, with rates of 2/100,000 person-years in women aged under 35,rising to
3032/100,000 person-years in women 85 years of age and older, with rates in men
of 4 and 1909 respectively (Cooper and Melton, 1992). Above 50 years of age
there is a female to male incidence ratio of approximately 2:1 (EULAR Online
Course, 2008). The highest incidence rates have been reported from Northern Europe (EULAR Online Course, 2008).
Overall, about 98% of hip fractures occur among people
aged 35 or more, 80% of which occur in women (due in part to the presence of
more elderly women than men). In Europe it has been estimated that in 2000
there were 178,777 hip fractures sustained by men over 50, and 711.223 by women
over 50 (Kanis and Johnell, 2005).
Most distal forearm fractures occur in women (the age-adjusted
female to male ratio being 4:1), and around 50% occur in women aged 65 or more.
A multicentre study in the United Kingdom found annual incidences of 9 and 37
per 10 000 men and women respectively, with hospitalization rates of 23% and
19% respectively (O’Neill et al, 2001). There was a tendency for the incidence
rate of distal forearm fracture to continue to increase after the age of 70
among women, perhaps pointing to increasing frailty in the elderly female
population of Western countries throughout the last decade of the twentieth
century and the first decade of the twenty-first.
Most fractures in subjects aged over 50 are the result of
osteoporosis. The incidence rates of proximal humeral, pelvic and proximal
tibial fractures also rise steeply with age and are greater in women than in
men. About 80% of proximal humeral fractures occur in individuals aged 35 or
more, three-quarters of which occur in women. Similar patterns have been
observed for distal femur fracture and fractures of the rib, clavicle and
scapula (Woolf and Pfleger, 2003).
5.6.3.4.4 Prevalence
Prevalence is best measured by the frequency of reduced
BMD or numbers of those with vertebral deformity.
The prevalence of vertebral deformity increases
with age and is present in one in eight men and women aged over 50 in Europe. The rates vary between populations with a demonstrated three-fold variation across Europe and up to two-fold variation within European countries in the EVOS study (O’Neill et
al, 2001). Vertebral deformities in men at the earlier ages may represent
developmental changes rather than fractures. The age-adjusted and sex-adjusted
incidence rates for vertebral deformity are 1% per year among women and 0.6%
per year among men from the European Prospective Osteoporosis Study (European
Prospective Osteoporosis Study, 2002). Similar figures have been found also in
the USA.
It is estimated that around 23% of women aged 50 or more
in the United Kingdom have osteoporosis at any site as defined by WHO (WHO
Technical Report 919, 2003). There is a steep increase in the proportion that
has osteoporosis between 50 and 80 years of age.
On the basis of the IOF criteria, the general prevalence
of osteoporosis rises from 5% in women at the age of 50 to 50% at the age of
85, whilst in men the comparable figures are 2.4% and 20%, respectively (Kanis
et al, 2000)
Determinants, risk factors and the population at risk
Apart from age and female gender, the major determinants
of fracture are falling, low bone mass, i.e. osteoporosis, and previous low
trauma fracture. There are risk factors that identify those more likely to fall
(Table 5.6.8) and those who may have osteoporosis or be at risk of fracture
(Table 5.6.9). There are some semi-independent risk factors for fracture such
as bone turnover as assessed by bone markers. Frailty and co-morbidity are also
risk factors for poor outcome of fracture (Woolf and Akesson, 2003).
Most hip fractures occur after a fall in men or women with
reduced bone strength. The risk of falling increases with age. Hip fracture may
also occur spontaneously (Melton, 1995).
Table 5.6.8. Risk Factors for
Falling in the Elderly
Table 5.6.9. Risk factors for bone loss, development of osteoporosis
and for fracture in the elderly (excluding falls)
Bone density has the strongest relationship with fracture
but many fractures will also occur in women without osteoporosis. The
possibility of fracture increases when combining low bone density with the
presence of other risk factors for fracture. In particular, bone density
combined with risk factors that are at least partly independent of bone density
(Cummings et al, 1995) can identify those at much increased risk of fracture
but the exact interaction of different risk factors has not yet been
established. Efforts are being made to use existing data to describe the
absolute risk for the individual patient over a time period that is
comprehensible, i.e. 5 to 10 years (Kanis et al, 2002) (Table 5.6.10).
Table 5.6.10. Estimated 10 year risks
of fractures in the UK at various ages
Disability
Hip fracture results in pain, loss of mobility and excess
mortality. Nearly all are hospitalised and most undergo surgical repair of the
fracture or replacement of the joint. At 1 year, hip fracture is associated
with 20% mortality or 50% loss of function, with only 30% regaining all prior
functions (Melton, 2003; Sernbo and Johnell, 1993). Many lose their
independence and require long-term care. Only half those surviving a hip
fracture will walk again and often not to the same level as prior to the
fracture (Magaziner et al, 1990; Sernbo and Johnell, 1993).
Acute vertebral fracture affects one’s quality of life
with limitation of activities and restriction of participation. Up to a fifth
are hospitalised and some will require subsequent long-term care, especially
those of advanced age or with comorbidity. Pain and loss of spinal movement
cause most limitations. Chronic vertebral osteoporosis, with progressive
compression fractures and deformities, is associated to pain and long-term
impairment of quality of life which worsens with each new vertebral fracture.
The effect is not just due to the recent fracture as it has been demonstrated
several years after the fracture. Physical performance declines even in the
absence of significant pain, whilst undiagnosed vertebral fractures are
associated with disability. Co-morbidity is common at this advanced age and
contributes to the impact on quality of life and increased mortality (Woolf and
Akesson, 2006).
Colle’s fracture results in hospitalisation rates of 23%
of men and 19% of women (O’Neill et al, 2001; Sernbo and Johnell, 1993). Only
50% report a good functional outcome at 6 months (Kaukonen et al, 1988; Sernbo
and Johnell, 1993).
Mortality
Mortality following hip fracture is high in the first
year, perhaps up to 25% in women and 35% in men (Cooper, 1997; Sernbo and
Johnell, 1993). Comorbidity is an important contributory factor in hip
fractures and a determinant of outcome (Cooper, 1997; Sernbo and Johnell,
1993).
Vertebral fractures are also associated with an increased
mortality at 5 years as seen with hip fracture, but this is gradual over the 5
year period. No excess mortality is associated with wrist fractures (Center et
al, 1999; Cooper et al, 1993; Johnell et al, 2004).
Future trends
The number of osteoporotic fractures is increasing
throughout Europe, and the number of hip fractures is projected to more than
double from 2000 to 2050. This is due to the ageing of the population and
changes in risk factors (Report on osteoporosis in the European Community
1998).
Low Back pain
Definition
Low back pain is a major health and socio-economic problem
in Western countries. Many people will experience one or more episodes of low
back pain in their lives. It is usually defined as pain localised below the
line of the 12th rib and above the inferior gluteal folds (Anderson, 1986),
with or without leg pain. It is usually classified as being “specific” or
“non-specific”. Specific back pain is defined as symptoms caused by a specific
pathophysiologic mechanism such as prolapsed intervertebral disc, infection,
spondyloarthropathy, fracture or tumour. Such specific causes account for about
10% of cases whereas 90% of people with low back pain have no clearly defined
pathophysiologic cause.
Non-specific low back pain is usually classified according
to duration and recurrence. Acute back pain is of less than 6 weeks duration;
subacute is between 6 weeks and 3 months duration and chronic when it lasts
more than 3 months (Frymoyer, 1988). Frequent episodes are described as recurrent
back pain.
Natural history
Most episodes of low back pain settle after a couple of
weeks but many have a recurrent course with further acute episodes affecting 20
– 44% within 1 year in the working population and lifetime recurrences of up to
85% (Andersson, 1999). Frequently it never fully resolves and is characterised
by exacerbations of chronic low back pain. Many people with chronic low back
pain also have widespread pain.
Incidence
There are not many studies of incidence but a large study
from the Netherlands reported an incidence of 28.0 episodes / 1000 people per
year; the incidence of low back pain with sciatica was 11.6 / 1000 people per
year, affecting men a little more than women, more frequent in the working
population and higher between 25 and 64 years of age (van den Velden et al,
1991). New episodes are twice as common if there is a history of previous low
back pain.
Prevalence
Lifetime prevalence varies between 58% and 84%. Back pain
is very common but the prevalence varies according to the definitions used and
the population studied. Non-comparability of surveys makes it difficult to
understand whether there are real differences between countries. Point
prevalence (proportion of population studied that are suffering back pain at a particular
point in time) is between 4% and 33% (Woolf and Pfleger, 2003).
Determinants, risk factors and the population at risk
The occurrence of low back pain is associated with age,
physical fitness, smoking, excess body weight and strength
of back and abdominal muscles. Psychological factors associated to the
occurrence of back pain are anxiety, depression, emotional instability and pain
behaviour. Occupational factors clearly play a role such as heavy work,
lifting, bending, twisting, pulling and pushing as well as psychological
workplace variables, such as dissatisfaction. Obesity is a risk factor for
chronicity.
Psychosocial aspects of health and work combined with
economic aspects have an impact on work loss attributed to back pain more than
physical aspects of disability and physical requirements of the job.
Impact on individual (morbidity, mortality) and on society
(socioeconomic)
Back pain has a marked effect on the individual and also
on society due to its frequency and economic consequences of work loss and
social support.
The problem is defined by pain, which is often persistent
during the episode with many that do not have complete resolution of their
symptoms and have flares on a background of chronic pain. Pain is often worse
with prolonged walking, standing and sitting - which restricts mobility - as
well as travelling any distance in a vehicle. Sleep is often disturbed and some
also have chronic widespread pain. Strenuous activities as well as leisure
pursuits may be prevented during the episode of back pain by worsening of the
pain and after the episode by fear of recurrence.
Most return to work within 1 week with 90% returning
within 2 months (Woolf and Pfleger, 2003), but the longer on sick
leave, the less likely the person is to return to work. After 6
months off work, less than 50% will return to work and after 2 years absence,
there is little chance of returning. Because of this aspect and its frequency,
the costs to society are enormous. About 90% of the cost of back pain is
indirect due to work loss and disablement reflecting its frequency among the
working population (European guidelines for prevention in low back pain http://www.backpaineurope.org/web/files/WG3_Guidelines.pdf). The costs are mainly
incurred by 10 – 25% of those with back pain persisting for more than 1 month.
In cases with chronic back pain, the impact on health and low frequency of
return to work probably reflects that about 50% of cases are associated to a
non-specific widespread pain condition.
Future trends
There has been a reported increase in prevalence in the UK between 1980 and 2000 (Palmer et al, 2000), but this is interpreted as related to a
greater awareness of minor back symptoms and willingness to report them. Such
cultural changes could lead to an enormous increase in the burden.
