Regional pain

Musculoskeletal symptoms are common in older middle life. In a survey of adults aged ≥50 years from North Staffordshire , back pain in the previous 4 weeks affected about one in three people aged 50–59 years. Similar proportions reported knee or shoulder pain, while a fifth to a quarter reported pains in the hip, neck, distal upper limbs or feet. Almost two-thirds of those affected experienced moderate to extreme interference with their work and household duties.

Age is a major risk factor for prevalent regional pain. Thus, in a random sample of the Dutch population , pain affecting the elbow, hip or foot was about 1.5 times more common in people aged 45–64 years than in those aged 25–44; in the Quebec Health Survey , odds of upper extremity pain causing frequent disturbance in work activity were raised by 1.7–3.4-fold in those aged ≥50 versus 18–24 years; in a survey of over 4000 adults from 16 British general practices , pain lasting for ≥3 months and ‘highly disabling or severely limiting’ affected 10% of 55–64-year-olds but was rare in young adults; and in a sample drawn from 40 British general practices, sciatica was five to eight times more common in people aged 55–65 than in those aged 16–24 years .

For uncomplicated low back pain (LBP), the trend with age is somewhat flatter and less consistent. Many studies have found a moderate age-related rise, peaking and flattening off in the second half of working life; but some have found little relation. In a review of 22 such investigations , <50% had reported a positive association. However, even in LBP, there is a general, if moderate, tendency for disabling effects to become commoner at older ages. In the Cultural and Psychosocial Influences on Disability (CUPID) study , comprising >12,000 workers across 47 occupational groups from 18 countries, disabling LBP was 55% more prevalent at 50–59 than at 20–29 years; and in a British population survey , the 12-month prevalence of troublesome LBP was roughly doubled in a similar age comparison.

The prevalence of disabling pain varies markedly by country and setting, even among workers doing jobs with similar physical exposures. Fig. 1 illustrates the variation, for example, in 1-month prevalence of disabling LBP and wrist/hand pain among 40–59-year-olds from the occupations and countries of the CUPID study . Such variation indicates that report of disability depends importantly on factors other than the work environment (see also Chapter 3).

The 1-month prevalence of disabling low back and wrist/hand pain by occupational group and country in workers aged 40–59 years from the CUPID study (adapted from Ref. ).

Women are more likely than men to report pain, which they attribute to work, for reasons that have been much debated . The impact of this on work capacity may be growing, as more women work nowadays and most of this growth has been seen in women >50 years of age.

Osteoarthritis

Symptomatic knee osteoarthritis (OA) affects ∼2.5–7% of adults aged 45–59 years and ∼7–15% of 60–69-year-olds worldwide . In the UK, the prevalence of knee pain in the over-40s is ∼20–28% , and half of cases have radiographic OA. Cartilage injury, a strong risk factor for knee OA, is fairly common at a population level , while asymptomatic defects in knee cartilage are highly prevalent in middle age .

In a probability sample of the US population, radiographic hip OA was confirmed in 2% of adults aged 55–59, 2.7% of those aged 60–64, and 3.4% of those aged 65–69 . Doctor-diagnosed OA was ∼20 times higher in 55–64-year-olds than in those aged 25–34 years .

Large joint OA is a major cause of disability, a growing proportion of which is borne by people who regard themselves still of working age. Thus, during 2010–2011, 92,000 primary knee joint replacements and 5800 revisions were performed in England and Wales (up over 4 years by 41% and 77%): one-third of replacements occurred in patients aged <65 years ; in Finland, 45% of implants are received by patients <65 years ; and in Denmark, 51% of hip replacements in 2010 took place before age 70 .

Rheumatoid arthritis

Rheumatoid arthritis (RA) is far less common than OA, but its prevalence rises steeply with age. In the National Health and Nutrition Examination Survey (NHANES I), doctor-diagnosed disease was 11 times higher in 55–64-year-olds than in 25–34-year-olds , while the incidence in the British Norfolk Arthritis Register was six times higher in this age group than in 15–24-year-olds .

Ankylosing spondylitis

Ankylosing spondylitis (AS) is usually thought of as a young person’s disease, but diagnosis is often delayed and symptoms tend to persist into later life. Thus, with suboptimal disease control, vocational handicap becomes more common with age.

Osteoporosis

This disease has rarely been studied in the occupational setting, in token of which our search for this review found no relevant hits on risks of osteoporotic fracture in older workers from manual occupations. Nonetheless, the overall 10-year risk of fracture from age 50 is in the order of 7–10%, reflecting the growing propensity to low-trauma osteoporotic fractures at older ages .

Regional pain

Musculoskeletal symptoms are common in older middle life. In a survey of adults aged ≥50 years from North Staffordshire , back pain in the previous 4 weeks affected about one in three people aged 50–59 years. Similar proportions reported knee or shoulder pain, while a fifth to a quarter reported pains in the hip, neck, distal upper limbs or feet. Almost two-thirds of those affected experienced moderate to extreme interference with their work and household duties.

Age is a major risk factor for prevalent regional pain. Thus, in a random sample of the Dutch population , pain affecting the elbow, hip or foot was about 1.5 times more common in people aged 45–64 years than in those aged 25–44; in the Quebec Health Survey , odds of upper extremity pain causing frequent disturbance in work activity were raised by 1.7–3.4-fold in those aged ≥50 versus 18–24 years; in a survey of over 4000 adults from 16 British general practices , pain lasting for ≥3 months and ‘highly disabling or severely limiting’ affected 10% of 55–64-year-olds but was rare in young adults; and in a sample drawn from 40 British general practices, sciatica was five to eight times more common in people aged 55–65 than in those aged 16–24 years .

For uncomplicated low back pain (LBP), the trend with age is somewhat flatter and less consistent. Many studies have found a moderate age-related rise, peaking and flattening off in the second half of working life; but some have found little relation. In a review of 22 such investigations , <50% had reported a positive association. However, even in LBP, there is a general, if moderate, tendency for disabling effects to become commoner at older ages. In the Cultural and Psychosocial Influences on Disability (CUPID) study , comprising >12,000 workers across 47 occupational groups from 18 countries, disabling LBP was 55% more prevalent at 50–59 than at 20–29 years; and in a British population survey , the 12-month prevalence of troublesome LBP was roughly doubled in a similar age comparison.

The prevalence of disabling pain varies markedly by country and setting, even among workers doing jobs with similar physical exposures. Fig. 1 illustrates the variation, for example, in 1-month prevalence of disabling LBP and wrist/hand pain among 40–59-year-olds from the occupations and countries of the CUPID study . Such variation indicates that report of disability depends importantly on factors other than the work environment (see also Chapter 3).

The 1-month prevalence of disabling low back and wrist/hand pain by occupational group and country in workers aged 40–59 years from the CUPID study (adapted from Ref. ).

Women are more likely than men to report pain, which they attribute to work, for reasons that have been much debated . The impact of this on work capacity may be growing, as more women work nowadays and most of this growth has been seen in women >50 years of age.

Osteoarthritis

Symptomatic knee osteoarthritis (OA) affects ∼2.5–7% of adults aged 45–59 years and ∼7–15% of 60–69-year-olds worldwide . In the UK, the prevalence of knee pain in the over-40s is ∼20–28% , and half of cases have radiographic OA. Cartilage injury, a strong risk factor for knee OA, is fairly common at a population level , while asymptomatic defects in knee cartilage are highly prevalent in middle age .

In a probability sample of the US population, radiographic hip OA was confirmed in 2% of adults aged 55–59, 2.7% of those aged 60–64, and 3.4% of those aged 65–69 . Doctor-diagnosed OA was ∼20 times higher in 55–64-year-olds than in those aged 25–34 years .

Large joint OA is a major cause of disability, a growing proportion of which is borne by people who regard themselves still of working age. Thus, during 2010–2011, 92,000 primary knee joint replacements and 5800 revisions were performed in England and Wales (up over 4 years by 41% and 77%): one-third of replacements occurred in patients aged <65 years ; in Finland, 45% of implants are received by patients <65 years ; and in Denmark, 51% of hip replacements in 2010 took place before age 70 .

Rheumatoid arthritis

Rheumatoid arthritis (RA) is far less common than OA, but its prevalence rises steeply with age. In the National Health and Nutrition Examination Survey (NHANES I), doctor-diagnosed disease was 11 times higher in 55–64-year-olds than in 25–34-year-olds , while the incidence in the British Norfolk Arthritis Register was six times higher in this age group than in 15–24-year-olds .

Ankylosing spondylitis

Ankylosing spondylitis (AS) is usually thought of as a young person’s disease, but diagnosis is often delayed and symptoms tend to persist into later life. Thus, with suboptimal disease control, vocational handicap becomes more common with age.

Osteoporosis

This disease has rarely been studied in the occupational setting, in token of which our search for this review found no relevant hits on risks of osteoporotic fracture in older workers from manual occupations. Nonetheless, the overall 10-year risk of fracture from age 50 is in the order of 7–10%, reflecting the growing propensity to low-trauma osteoporotic fractures at older ages .

Soft tissue rheumatism and OA

Musculoskeletal complaints commonly underlie reduced work participation. In one systematic review , 25 studies were found on MSDs and disability pensioning, encompassing 58,000 workers. The pooled relative risk (RR) for disability pensioning was elevated two- to threefold in those with MSDs. Among included studies, risks of pensioning were more than doubled in nursing aids with inflammatory disease or frequent LBP , increased 2–3-fold in Danish municipal workers affected by MSDs of hips and knees , and approximately three times more likely in Finnish civil servants with musculoskeletal symptoms relative to other workers. When 24,000 twins from Finland were followed over three decades, disability pensioning due to any MSD occurred in 7.6% of the sample, a third of this ascribed to OA . In Greek nurses, absenteeism attributed to knee pain was ∼12 times more common after ≥45 than at ≤30 years .

Associations with job loss appear to be general to impaired musculoskeletal health, rather than specific to anatomical site or pathology. Thus, disability pensioning has been linked with pain in the low back, hips and knees, as described above , but also after other patterns of regional pain and with arthritis. In 3318 Danish employees followed over 2 years, long-term sick leave, disability retirement, and early retirement pensioning were related to neck or shoulder pain at baseline (RRs ∼1.6–1.9) ; in the Kuopio Ischaemic Heart Disease Risk Factor Study, odds of disability retirement were increased for those at baseline with a back problem, OA, RA or a history of serious previous injury ( Table 1 ). In the British North Staffordshire Osteoarthritis Project (NorStOP) study, 25% of employed patients consulting a family doctor with OA had left the workplace 3 years later ; in the five European countries National Health and Wellness Survey, among a sample of mainly middle-aged interviewees, OA was frequently linked with unemployment, absenteeism and presenteeism ; while in the Australian ‘45 and Up’ study, treatment for OA in the previous month carried a twofold higher risk of ill-health retirement .

Associations have also been found with a physician’s diagnosis of MSD and with frequently taken analgesia. Thus, in the Finnish twins study, those taking analgesic drugs on >10 days/year were twice as likely to receive an MSD-ascribed disability pension during the subsequent three decades .

Sick leave is a strong predictor of future disability pensioning. In a French cohort of 20,434 utility workers, sick leave of >7 days for an MSD in 1990–92 carried a >3–4.6-fold higher risk of disability pensioning over a 13-year follow-up ; in a population sample of 176,600 Swedes, those with sick leave of >7 days for an MSD in 1985 were 5.7 times more likely than those without to take an MSD-related disability pension in 1991–96 .

Whilst the association between musculoskeletal ill-health and job loss is rather non-specific, more severe or extensive symptoms appear consistently to carry a higher risk of poor employment outcome. For example, in a Norwegian study, the odds of disability pensioning over 14 years rose monotonically with number of painful anatomical sites in the year before baseline, being approximately fourfold higher in those with nine or 10 painful sites ; in another population survey from Norway, long-term disability was 3.5 times more likely in those with generalised pain in the week before baseline than in those with localised LBP ; and among Finnish workers attending occupational health services with upper limb pain, >50% reported reduced productivity at work , the main risk factors among older employees being high pain intensity and pain-related sleep disturbance (odds ratio (OR) 6.0 in the top tertile), rather than diagnosis.

Inflammatory arthritis

In general, RA is a more disabling condition than OA or soft tissue rheumatism, and has a more profound impact on employment. Disability begins early, rises linearly with time and, within 10 years of disease onset, >50% of patients fail to maintain a full-time job . In a large cohort with RA, only 10% remained in employment 30 years after disease onset . Job retention rates were lower in occupations with high physical demands than when work was flexible and self-paced. Similarly, when economically active patients with RA from the Norfolk Arthritis Register were followed for ∼8.6 years, one-third had stopped work for health reasons at a rate 32 times greater than a matched control group .

In outpatients with AS, psoriatic arthropathy and systemic lupus erythematosus (SLE), enrolled into a national German database, those aged 50–70 years had disability pension rates of 28%, 32% and 61%, respectively, versus 37% for patients with RA . The costs ascribed by the human capital approach to lost work productivity were estimated at 82%, 87% and 145% of those for similarly aged outpatients with RA. Although comparison between diseases of differing age at onset is not straightforward, these findings suggest that inflammatory arthropathies of various kinds can have a substantial career-limiting impact on patients’ ability to work. Further evidence on this comes from Dutch employment data on patients with AS ( Fig. 2 ) . Among those initially in work, the age-, sex-adjusted withdrawal rate over follow-up was three times that in the general population, notably in men with a manual job (elevated 5.2-fold), although still doubled in white-collar occupations .

Proportion (%) of men in the Dutch population in full-time employment, by age and health status: men with ankylosing spondylitis versus all men (adapted from Boonen et al. ).

Co-morbidities

Workers with MSDs may cope less well if they have concurrent medical problems which otherwise might be compatible with working. In evidence of this, one report found that among patients with arthritis, those who were also clinically depressed were significantly more likely to become work-disabled . Treatment of depression in people with OA lessens their pain intensity and the interference with daily activities of their arthritis , and so perhaps benefits their work participation.