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Keywords:

  • Joint pathology;
  • Musculoskeletal pain;
  • Functional ability

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

Objective

To establish the prevalence of multiple joint problems and their impact on everyday tasks.

Methods

A random sample of the UK population was assessed using a postal questionnaire. Data on overall joint pain, swelling and stiffness, and activities of daily living were obtained from 16,222 individuals >55 years of age (86% response rate). Prevalence estimates of joint problems were established and the impact of multiple joint pathologies on common physical tasks was determined.

Results

Single joint involvement was unusual (median joint involvement 4). Although the knee was the most frequently involved joint (220.30 per 1,000), isolated knee pathology accounted for only 1 in 11 patients with knee pain. Although single joint disorders increased the risk of experiencing functional difficulty, this risk was substantially increased with multiple joint problems: individuals with knee and feet problems were 14 times more likely to experience difficulty standing and walking than those without knee problems (odds ratio [OR] 14.50); knee and hip problems increased the risk >12 times (OR 12.43) whereas knee, back, feet, and hip involvement increased the risk 60 times (OR 62.41).

Conclusion

Multiple-site joint problems are much more common than single joint problems. Although individual joint problems have a considerable impact on a person's functional ability, this risk is substantially increased when other joints are involved. With the increasing burden associated with the aging population, it is essential that the management of joint pain be considered in light of the impact of multiple, rather than single, joint problems.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

It has been estimated that 15% of the adult population have musculoskeletal problems (1), with 2 out of 3 persons over the age of 50 reporting recent musculoskeletal pain (2). Individuals reporting such pain represent a considerable direct and indirect cost to health care services (3, 4) and are more likely to have poorer general health (5) and greater levels of depression (6), anxiety (7), physical disability (2, 8), and associated lost productivity in the workforce (9, 10). Although there is some limited recognition that the presentation of multiple joint problems is common (2), the focus of management strategies is still aimed at individual joint problems: indeed, the functional impact on daily tasks of the most common multiple joint combinations has not been explored. The purpose of this study was to determine the prevalence and associated functional limitations of joint problems in the older age community, and to evaluate the impact of each joint separately and the interaction of multiple-site joint problems on physical abilities.

PATIENTS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

A community-based postal survey, approved by the North Yorkshire local ethics committee, was originally commissioned by North Yorkshire Health as part of a study to determine the prevalence of knee and hip problems in the community in the 1990s (11, 12). Names of 18,227 individuals >55 years of age were selected randomly from the North Yorkshire Family Health Services Authority, which is coterminous with North Yorkshire District Health Authority. The population estimate for the group >55 years of age in this population is 210,000. The postal questionnaire was used to describe population estimates of joint problems and to identify patients with functional limitations associated with joint pathology. Individuals with knee problems were invited to complete a more comprehensive questionnaire, which formed the basis of the work that has been published elsewhere (11). The data used in this study were from the first questionnaire and have not been published previously. The questionnaire asked for demographic information and clinician-diagnosed comorbidities (Figure 1). Participants were asked if they had experienced any swelling, pain, or stiffness in any of their joints, neck, or back that lasted >6 weeks in the previous 3 months. To establish loci of pain, participants indicated the location of joint problems on a manikin, with major joints identified on the manikin as boxes. Participants were also asked to indicate if they experienced difficulties with a number of activities of daily living or required assistance with daily tasks, as described in Figure 1.

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Figure 1. Questions included in the mail-out questionnaire.

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Statistical analysis.

Once completed questionnaires were received, the data were explored for nonresponse bias. Participants who responded were slightly younger than nonrespondents (mean age 66.5 versus 66.3 years; t = 5.0, P = 0.01), and women were more likely to respond compared with men (56.5% versus 43.5%; χ2[1] = 46.6, P = 0.01). Data were therefore weighted by age and sex to adjust for nonresponse bias to determine prevalence estimates, with 95% confidence intervals calculated according to the method described by Schoenberg (13). Data for hands and wrists were combined and are presented as hand data, as were data for feet and ankles, which are presented as foot data. In the first analysis, joint pain in either the right, left, or both joints was considered a positive response for that joint and data in subsequent analyses were explored for the impact of unilateral and bilateral pain. Data were analyzed using the Statistical Package for the Social Sciences version 11.01 (SPSS, Chicago, IL). For all modeling and inferential statistics, data were analyzed in unweighted form. Site of joint problems, presence of ≥1 comorbidities, sex, and age and were used in logistic regression modeling to quantify the risk or likelihood of having difficulties with activities of daily living. To determine the contribution of joints to functional problems (including site of joint pain, the most common joint combinations, and then unilateral and bilateral presentations), each was included in a forward stepwise logistic regression model. Multicollinearity of variables was assessed using a 2-step approach. First, all variables were assessed for correlation. No variables demonstrating an association >0.9 were included in the model (14). In fact, the highest correlation between any of the variables was between elbow and hand problems, and this was a poor association (rho = 0.273). Following this process, Hosmer-Lemeshow goodness-of-fit statistic was calculated for each of the functional indicators, and all models fulfilled the criteria and were accepted. Variables were investigated for both main and interaction effects (14), and the summative odd risks for joint combinations included the main and interaction effect of the joints involved and based on that described in the literature (15–17).

Although data for several functional indicators were captured, only those with a predictive capacity greater than R2 = 0.250 were included. Data captured for putting on shoes, brushing hair, gripping things, regular general practitioner visits, hospital specialists' visits, prescription medication, and nonprescription medication were not included in the final analysis.

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

Prevalence estimates.

Completed questionnaires were received from 16,222 individuals (response rate 86%) (11). Of the respondents, 39.11% reported joint pain, swelling, or stiffness in their joints over the last 3 months that lasted ≥6 weeks, with higher rates in women (417.55 per 1,000 individuals in the community compared with 330.34 per 1,000 in men; χ2[1] = 148.966, P < 0.001) and the older age group (362.73 in persons age 55–64 years compared with 409.71 in persons age ≥75 years; χ2[2] = 93.135, P < 0.001). Individuals with joint problems were also more likely to report comorbidities than individuals without joint problems (χ2[1] = 30.635, P < 0.001).

Multiple joint presentation.

Prevalence estimates for joint pain, swelling, and/or stiffness per 1,000 for each site are presented in Table 1. The median reported number of joints involved was 4 (range 1–8; 25th quartile = 2, 75th quartile = 8.00). Only 1 (12.5%) in 8 individuals who reported joint problems experienced problems in a single joint (Table 2). Only 1 in 11 respondents reported pain only in the knee, which was the most common problem joint. The most common joint combinations are presented in Table 2. Problems with the knees and feet, the knees and back, or the knees and hands were also regularly reported. The ratio of single to multiple joint problems was even greater in the hands, feet, shoulders, neck, hips, and elbows.

Table 1. Prevalence estimates of joint pain, swelling, and/or stiffness over the last 3 months lasting >6 weeks per 1,000 for each joint*
Joints/age, yearsMaleFemaleTotal
  • *

    Values are the prevalence estimates (95% confidence interval). Estimates have been adjusted for age and sex.

Neck total125.26 (112.83, 138.49)171.74 (157.85, 185.63)151.54 (138.24, 168.84)
 55–64130.80 (118.18, 143.42)174.57 (160.61, 188.53)153.11 (139.76, 166.46)
 65–75130.98 (118.35, 143.61)173.48 (159.55, 187.41)154.24 (140.86, 167.62)
 ≥75106.14 (94.44, 117.84)167.24 (153.48, 181.00)146.32 (133.18, 159.46)
Shoulder total131.38 (118.74, 144.02)182.80 (168.62, 196.98)160.45 (146.88, 174.02)
 55–64136.84 (124.01, 149.67)159.03 (145.51, 172.55)148.15 (134.96, 161.34)
 65–75125.51 (113.07, 137.95)179.48 (165.38, 193.58)155.05 (141.64, 168.46)
 ≥75130.61 (117.99, 143.23)209.60 (194.77, 224.43)182.56 (168.38, 196.74)
Back total134.33 (121.59, 147.07)183.48 (169.28, 197.68)162.12 (148.51, 175.73)
 55–64144.60 (131.52, 157.68)177.77 (163.72, 191.82)161.50 (147.90, 175.10)
 65–75135.13 (122.36, 147.90)182.41 (168.24, 196.58)161.00 (147.42, 174.58)
 ≥75114.30 (102.28, 126.32)190.20 (175.83, 204.57)164.22 (150.54, 177.90)
Elbow total59.51 (50.07, 68.95)73.64 (63.42, 83.86)67.50 (57.61, 77.39)
 55–6477.67 (67.25, 88.09)73.85 (63.62, 84.08)75.72 (64.89, 85.55)
 65–7548.52 (39.77, 57.27)63.71 (54.03, 73.39)56.83 (47.55, 66.11)
 ≥7543.54 (35.13, 52.15)83.24 (72.54, 93.94)69.65 (59.64, 79.66)
Hands total133.44 (120.73, 146.15)233.66 (218.32, 249.00)190.09 (175.72, 204.46)
 55–64135.60 (122.81, 148.39)214.91 (199.96, 229.86)176.02 (162.02, 200.02)
 65–75142.26 (129.59, 155.61)233.20 (217.87, 248.53)192.03 (177.61, 206.45)
 ≥75115.65 (103.58, 127.72)252.66 (236.96, 268.36)205.76 (191.02, 220.50)
Hip total94.43 (83.22, 105.64)151.53 (138.23, 164.83)126.71 (114.23, 139.19)
 55–6499.34 (87.92, 110.76)137.68 (124.82, 150.54)118.88 (106.69, 131.07)
 65–75102.08 (90.55, 113.61)144.43 (131.35, 157.51)125.26 (112.83, 137.69)
 ≥7573.46 (63.25, 83.67)172.26 (158.36, 186.16)138.44 (125.56, 151.32)
Knee total176.64 (162.62, 190.66)253.92 (238.20, 269.64)220.33 (205.26, 235.40)
 55–64168.77 (154.97, 182.57)207.80 (193.01, 222.59)188.66 (174.33, 202.99)
 65–75187.40 (173.10, 173.10)241.84 (226.34, 257.34)217.20 (202.20, 232.20)
 ≥75174.15 (160.20, 188.10)311.51 (294.91, 328.11)264.48 (248.57, 280.39)
Feet total136.28 (123.47, 149.09)221.28 (206.19, 236.37)184.33 (170.11, 198.55)
 55–64130.48 (117.87, 143.09)186.98 (172.69, 201.27)159.28 (145.75, 172.81)
 65–75140.57 (127.62, 153.52)207.18 (192.40, 221.96)177.02 (162.99, 191.05)
 ≥75140.17 (127.23, 153.11)269.17 (253.18, 283.16)225.01 (209.84, 240.18)
Table 2. Prevalence of single joint problems per 1,000*
Specific jointPrevalence of specific joint problems alonePrevalence when the specific joint is involvedAll joint problems:specific joint problem alone ratioMost common joint combinations with specific joint
  • *

    Values are the prevalence estimates (95% confidence interval) unless otherwise indicated. Estimates have been adjusted for age and sex.

Knee18.95 (12.58, 25.12)220.33 (20.526, 235.40)11.63:1Knee and feet Knee and back Knee and hands Knee and hips
Hands7.13 (2.51, 11.75)190.09 (175.72, 204.46)26.66:1Hands and knees Hands, knees, and feet Feet and hands
Feet4.87 (0.71, 9.03)184.33 (170.11, 198.55)37.85:1Feet and knees Feet, knees, and hand Feet, knees, and hip Feet and hands
Back13.59 (7.97, 19.21)162.12 (148.51, 175.33)11.93:1Back and knees Back and neck Back, knee, and feet Knee, back, feet, and hip
Shoulders6.74 (2.19, 11.29)160.45 (146.88, 174.02)23.81:1Shoulder and neck Shoulder and knee
Neck7.69 (2.97, 12.41)151.54 (138.24, 168.84)19.71:1Neck and shoulder Neck and back Neck and knee
Hips6.42 (1.93, 10.91)126.71 (114.23, 139.19)19.74:1Hips and knees Hip, knees, and feet Hip, back, knee, and feet
Elbows1.55 (−1.65, 4.75)67.50 (57.60, 73.39)43.55:1Elbow and shoulder

Indicators of functional ability.

Logistic regression modeling for standing and walking is presented in Table 3. Almost one-third of all respondents reported difficulty walking and standing (32.16%). When adjusted for sex, age, and the presence of comorbidities, persons with individual joint problems reported 2–3 times more difficulty with walking and standing than those without joint problems (R2 = 0.408): persons with hip problems were >3.5 times more likely to report difficulty than those without hip problems (odds ratio [OR] 3.7173, P < 0.001); persons who reported knee problems were 3 times more likely to report difficulty than those with no knee problems (OR 3.0205, P < 0.001); and those with feet problems were 2.5 times more likely to report difficulty than those with no feet problems (OR 2.5907, P < 0.001). Individuals who reported back problems were slightly under 2 times more likely to report difficulty than those with reported joint problems without back pathology (OR 1.9374, P < 0.001), and those with neck problems were less likely to report difficulty with standing and walking compared with those with no neck problems (OR 0.0563, P < 0.001).

Table 3. Logistic regression modeling for standing and walking*
SiteCoefficient (β)Standard errorWald χ2POR95% CIPrevalence (per 1,000)
  • *

    This table presents a summary of the main effects for each of the individual joint sites (R2 = 0.408). Coefficient (β) = the mathematical weighting of each variable in the model; standard error = the estimated error of the mathematical weighting; OR = odds ratio; 95% CI = 95% confidence interval for the estimated odds ratio.

Constant0.61720.451     
Main effects       
 Comorbidities1.57540.1365133.17280.0004.83293.6983, 6.3155404.39
 Hip1.31300.177354.83430.0003.71732.6260, 5.2620126.71
 Knee1.10540.122880.97130.0003.02052.3742, 3.8427220.33
 Foot0.95190.104083.84120.0002.59072.1131, 3.1762184.33
 Back0.66140.100543.29300.0001.93741.5910, 2.3593162.12
 Neck−2.87650.444041.97260.0000.05630.0236, 0.1345151.54
 Shoulder0.25330.10465.86490.0151.28831.0495, 1.5814160.45
 Elbow−0.18630.13311.95940.1620.83010.6395, 1.077467.50
 Hands0.31990.10758.85190.0031.37701.1154, 1.7001190.09
 Age: 55–64 years−1.00220.129360.04090.0000.36710.2849, 0.4730 
 Female sex−0.12950.10481.52760.2160.87850.7155, 1.0788 

One-quarter (25.81%) of the cohort reported difficulties going up and down stairs, and this was particularly influenced by the joints of the lower limb (Table 4). Respondents with individual joint problems reported difficulty with this task (R2 = 0.344): those with knee problems were 3.5 times more likely to report problems than those without knee pathology (OR 3.4720, P < 0.001); those with feet problems were slightly under 2.5 times more likely than those with no foot pathology (OR 2.3978, P < 0.001); and those with hip problems were slightly over 2.5 times more likely to report difficulty compared with those without hip problems (OR 2.5883, P < 0.001). Most of the upper-limb problems did not influence the risk of difficulty significantly, with the exception of the neck; individuals with neck problems were 6 times less likely to report difficulty than those without neck problems (OR 0.1562, P < 0.001).

Table 4. Logistic regression modeling for going up and down stairs*
SiteCoefficient (β)Standard errorWald χ2POR95% CIPrevalence (per 1,000)
  • *

    This table presents a summary of the main effects for each of the individual joint sites (R2 = 0.344). See Table 3 for definitions.

Constant−0.46610.3748     
Main effects       
 Comorbidities1.17920.140470.56750.00003.25182.4696, 4.2816404.39
 Hip0.95100.124957.97960.00002.58832.0263, 3.3062126.71
 Knee1.24470.1079133.09220.00003.47202.8102, 4.2896220.33
 Foot0.87450.111861.21010.00002.39781.9260, 2.9851184.33
 Back0.34230.097212.41080.00041.40821.1640, 1.7036162.12
 Neck−1.85670.365225.84780.00000.15620.0763, 0.3195151.54
 Shoulder0.11620.10251.28510.25691.12320.9188, 1.3730160.45
 Elbow0.13200.12311.15000.28351.14110.8965, 1.452367.50
 Hands0.17940.10313.03030.08171.19650.9777, 1.4643190.09
 Age: 55–64 years−1.05820.122374.91610.00000.34710.2731, 0.4411 
 Female sex−0.07800.10110.59580.44020.92490.7587, 1.1276 

For difficulty in rising from a seated position, 20.80% of all respondents reported difficulty. Respondents with hip problems or knee problems were 3 times more likely to report difficulty (hip: OR 3.1321, P < 0.001; knee: OR 3.3074, P < 0.001; R2 = 0.276); those with back problems were 2.5 times more likely to report difficulty (OR 2.4297, P < 0.001); those with feet problems were 2 times more likely to report difficulty (OR 1.9873, P < 0.001); those with shoulder problems were 24% more likely to report difficulty (OR 1.2368, P = 0.0353); and those with hand problems increased their risk by 34% (OR 1.3402, P < 0.001). Respondents who reported neck problems were less likely to report difficulty in rising from a seated position than those without neck problems. Data are presented in Table 5.

Table 5. Logistic regression modeling for rising from a seated position*
SiteCoefficient (β)Standard errorWald χ2POR95% CIPrevalence (per 1,000)
  • *

    This table presents a summary of the main effects for each of the individual joint sites (R2 = 0.276). See Table 3 for definitions.

Constant−0.43000.3677     
Main effects       
 Comorbidities0.89410.139241.27780.00002.44511.8614, 3.2118404.39
 Hip1.14170.173043.54530.00003.13212.2313, 4.3964126.71
 Knee1.19620.164153.13780.00003.30742.3978, 4.5621220.33
 Foot0.68680.100346.85300.00001.98731.6325, 2.4191184.33
 Back0.88780.160430.62140.00002.42971.7742, 3.3274162.12
 Neck−2.00730.366629.97810.00000.13440.0655, 0.2756151.54
 Shoulder0.21250.10104.42820.03531.23681.0147, 1.5075160.45
 Elbow0.08560.11810.52500.46871.08930.8642, 1.373167.50
 Hands0.29290.10078.45540.00361.34021.1002, 1.6327190.09
 Age: 55–64 years−0.79250.118644.66630.00000.45270.3588, 0.5712 
 Female sex−0.33550.100011.26180.00080.71500.5878, 0.8697 

Multiple-site problems.

If we look at the most common joint combinations, the penalty for having multiple joint involvement becomes clear (Table 6). Whereas individuals with knee problems were 3 times more likely to report difficulty in walking and standing than individuals without knee problems, this risk increased dramatically for those with concomitant feet (OR 14.5048, P < 0.001), back (OR 10.8478), or hip problems (OR 12.4344). Respondents with knee, back, feet, and hip problems were 60 times more likely to report difficulty than those without problems in these joints. A similar pattern emerged with going up and down stairs: persons with knee and hand problems were 2.5 times more likely to report difficulty compared with those without knee and hand problems (OR 2.6064) and those with combined knee and shoulder problems (OR 2.4468). Once again, respondents with knee, back, feet, and hip problems increased their risk of difficulty by 20-fold (OR 20.6380). Respondents with combined knee and feet and knee and hip problems had a 5-fold increase in reporting difficulty using stairs compared with those without such joint pathology (OR 5.2233 and 5.6383, respectively).

Table 6. Combined odds ratio for the most common multiple joint problems for each of the functional indicators*
Joint combinationStanding and walkingClimbing stairsSeated position
  • *

    Values are the odds ratio (95% confidence interval). Combined odds ratios are a summative calculation taking into account the odds ratio for each joint plus the odds ratio for the interactions between all significant joint combinations.

Knee and feet14.50 (9.30, 22.62)5.22 (3.40, 8.03)4.05 (2.55, 7.18)
Knee and back10.85 (7.00, 16.81)3.33 (2.05, 4.58)1.93 (1.15, 8.96)
Knee and hands7.71 (4.91, 12.11)2.61 (1.72, 3.94)1.73 (1.72, 4.85)
Neck and shoulder0.13 (0.05, 0.39)0.11 (0.04, 0.28)0.11 (0.04, 0.27)
Knee and hips12.43 (4.45, 34.71)5.64 (1.38, 8.24)2.21 (0.36, 11.37)
Knee, hands, and feet19.97 (10.37, 38.46)2.61 (1.73, 11.76)1.73 (0.11, 11.72)
Knee and shoulders7.21 (4.62, 11.26)2.45 (1.62, 3.70)1.60 (1.08, 2.37)
Back and neck0.20 (0.07, 0.59)0.15 (0.06, 0.34)0.21 (0.08, 0.60)
Knee and neck0.32 (0.10, 0.96)0.34 (0.13, 0.86)0.17 (0.10, 0.82)
Knee, back, and feet28.10 (14.80, 53.38)7.97 (3.95, 13.69)6.45 (1.73, 15.76)
Knee, back, feet, and hip62.41 (14.97, 260.12)20.64 (2.59, 14.97)16.82 (3.66, 86.24)
Feet and hands6.61 (4.37, 10.01)1.80 (0.79, 2.05)1.73 (1.17, 2.57)

When the common combinations of joint problems were analyzed for rising from a seated position, the likelihood of reporting difficulty for this category was also increased. Those who reported knee and feet problems had a 4-fold increase in risk (OR 4.0488) and those who had knee and hip problems increased their risk by >2 (OR 2.2103). Of note, respondents with knee, hip, and hand problems had a 10-fold increased risk of reporting difficulty in this task (OR 10.3483). Individuals with knee and feet problems (OR 4.0488) had an increased risk in reporting difficulty compared with individuals with either knee or feet problems alone.

Unilateral versus bilateral joint problems.

To explore the impact of unilateral pain or bilateral pain at each site, logistic regression modeling was repeated for each of the joint sites for main effects and was compared by analyzing the log likelihood statistics (14). The predictive capacity of each of the functional activities was only increased marginally: for using stairs, the predictive capacity increased from R2 = 0.321 to R2 = 0.330; for walking and standing, it increased from R2 = 0.347 to R2 = 0.349; and for rising from a seated position, it increased from R2 = 0.264 to R2 = 0.271 for the most influential joints, which were the knee, hip, and feet. As expected, bilateral pain increased the risk of reporting difficulty with each of the functional tasks compared with unilateral problems (Table 7): bilateral knee problems increased the difficulty in using stairs by 3.5 compared with no knee pain, whereas pain in only 1 knee increased the risk by 2. In general, there was an increased difficulty reported when both joints were affected compared with unilateral joint problems, and these figures averaged out to those reported when unilateral and bilateral joint problems were considered simply as joint pain.

Table 7. Logistic regression modeling unilateral and bilateral problems at the major joints of the lower limb*
 Going up and down stairsWalking and standingRising from a seated position
  • *

    Values are the odds ratio (95% confidence interval). Modeling included joint site, sex, age, and comorbidities as main effects.

Knees   
 1 knee2.014 (1.924, 2.097)1.975 (1.897, 2.057)1.387 (1.332, 1.445)
 Both knees3.628 (3.493, 3.767)2.644 (2.545, 2.748)2.289 (2.157, 2.354)
Hips   
 1 hip1.540 (1.478, 1.605)2.059 (1.972, 2.150)1.887 (1.804, 1.954)
 Both hips2.646 (2.517, 2.782)3.031 (2.880, 3.219)3.023 (2.882, 3.170)
Foot and ankle   
 1 foot1.364 (1.283, 1.449)1.726 (1.623, 18.35)1.146 (1.077, 1.219)
 Both feet1.941 (1.876, 2.008)2.512 (2.424, 2.604)1.713 (1.665, 1.773)

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES

The purpose of this study was to report the prevalence, pattern, and impact of multiple joint problems in the community. Almost 40% of individuals >55 years of age in this community cohort reported some pain, swelling, or stiffness lasting >6 weeks over the previous 3-month period. In addition to high prevalence, joint pathology represented a substantial impact on a person's ability to undertake common functional tasks.

Although the prevalence of individual joint problems was similar to that previously reported (2, 18–22), this study demonstrated that multiple rather than single joint problems were common (median joint count of 4). While >20% of persons over the age of 55 had knee problems, <1 in 11 of this group reported pain only in the knee (Table 2). Other joints were found to have even higher ratios of multiple joint problems, such as in the hip, where only 1 in 20 respondents reported hip-only pain, and the feet, where only 1 in 38 respondents reported foot-only pain.

Not surprisingly, specific joint problems contributed to the difficulty that individuals had in undertaking particular tasks related to the upper or lower limbs. Individuals with knee problems were more likely to report difficulty in tasks associated with locomotion, such as standing and going up and down stairs. Those with hip problems were more likely to experience difficulty in rising from a seated position. Of note, the impact of feet and ankle problems, which have been rarely documented in the literature, was similar to that reported for knee and back problems.

The presence of bilateral joint problems increased the likelihood of difficulty in using stairs, rising from a seated position, and standing and walking compared with unilateral pathology only. However, this increase was only minor in comparison with joint problems that occurred in combination. For example, knee and feet pathology increased the risk of functional impairment, which was much greater than if the risk of difficulty for each of the individual joint problems was simply added together. The most obvious example of this exponential increase in difficulty was the impact of a combination of knee, back, feet, and hip problems, which increased the risk of difficulty in climbing stairs by 20 and walking by 60.

The impact of upper-limb joint problems on locomotor tasks was generally insignificant or actually reduced the risk of difficulty in the tasks associated with locomotion. The exceptions to this were the hands and shoulders, both of which increased the risk of difficulty in walking/standing and in rising from a seated position. We attempted to investigate functional tasks that we predicted would be related to upper-limb joint pathology (such as gripping and holding things); however, the resulting poor predictive capacity precluded these results being reported.

These data suggest that there is a gap in the management of joint problems, with the vast majority of publications and guidelines being focused on single joints. In published guidelines of management of the knee and hip osteoarthritis (23–25), there is no mention of multiple-site assessment and management. Indeed, the prevalence of multiple joint pathologies may explain some of the conflicting issues between research and clinical practice. Studies evaluating knee osteoarthritis often specifically exclude multiple joint presentations (26–28). Our data therefore suggest that such studies may not be generalizable to the majority of patients with osteoarthritis of the knee.

Although the ability to undertake functional tasks is influenced by many factors, it is important to note the significance of comorbidities. Our data considered the effect of comorbidities in the logistic modeling, and it is important to recognize that when considered as a main effect, comorbidities were the single greatest predictor of who would report difficulty in standing/walking and going up and down stairs. Comorbidities were second only to the hip as the single main influence on rising from a seated position. So although we understand that the presence of comorbidities in the older population is high (29), particularly in persons with pain (4) and joint pathologies (30, 31), they must be considered as an important factor in the ability to undertake simple functional tasks. Once again, exclusion of comorbidities in clinical trials seriously limits their generalizability in older populations.

The limitations of this study are acknowledged. Although it has been suggested that self reporting can be unreliable (32) and can overestimate specific joint pathology, the prevalence figures reported here are similar to those reported in much more rigorously validated data sets reported on hip pathology (33) and knee pathology (34). We also recognize that other variables that were not considered in the logistic regression modeling may also be likely to impact on functional ability.

Recent data suggest that the cost associated with musculoskeletal pain has extensive economic consequences for the community (3, 35), and with target estimates of the global burden of musculoskeletal conditions (36) increasing with the aging population, it is essential that appropriate strategies be addressed. Our data suggest that urgent changes need to be made in the understanding and management of joint problems and that a holistic approach to patient care is required.

There is a high prevalence of joint problems in the older community, which increases with age and is more common in women. Multiple-site involvement of pain is extremely common and the impact and interaction of the different sites of pain will substantially influence an individual's ability to undertake tasks of daily living. While comorbidities are high in this group, they also have a considerable influence, often above and beyond that of joint problems, on a person's functional impairment. Assessment and management strategies need to reflect the interaction of different sites of joint pain and the presence of comorbidities. In light of our findings, we suggest that assessment of a joint in isolation has limited value. The implications of multiple joint involvement are considerable: there is clearly a need for changes to assessment, referral, and therapeutic strategies, and a holistic approach to patient care is required.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. PATIENTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. REFERENCES