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Mar 21

Osteoporosis in older men: the CHAMP study

Journal reference: Bleicher K, Naganathan V, Cumming RG, et al. Prevalence and treatment of osteoporosis in older Australian men: findings from the CHAMP study. MJA 2010;193:387-391 [1]

Link: http://www.mja.com.au/public/issues/193_07_041010/ble10100_fm.html

Published: 4 October 2010

Evidence cookie says...

Osteoporosis is very common in men aged over 70 years and probably under-recognised and undertreated; 25% of participants had osteoporosis.

However, only 5% of the participants had a history of low trauma fracture.  Even in these men, the rate of treatment was very low.

Remember to discuss osteoporosis risk in older men and ask for a history of low impact trauma.  If bisphosphonate therapy is initiated, remember to co-prescribe oral calcium and vitamin D.

More details:


Article details


Study design:

cross-sectional analysis of epidemiological study


Study aim:

to determine the proportion of older men who met the Pharmaceutical Benefits Scheme (PBS) criteria for osteoporosis-specific treatments (bisphosphonates) who were actually receiving treatments


Methods summary:

  • Data from the Concord Health and Ageing in Men Project (CHAMP)
  • Recruitment of men aged 70  and up from three local government areas surrounding Concord Hospital
    • Between 2005-2007
    • NSW electoral roll data
    • Invitation sent to 3627 men and contact made with 3005 men
    • 190 men were excluded as no longer living in local area
    • Of remaining 2815 men, 1511 participated in the study (54%)
    • An additional 194 eligible men volunteered to take part in the study prior to receiving the invitation letter after hearing about it from friends and local media
  • Bone mineral density (BMD) measurements of the lumbar spine and right hip by dual x-ray absorptiometry (DXA)
    • Only 1626 men completed all DXA scans
    • 25 were unable to complete due to bilaterally total hip replacements
    • 53 were unable to complete due to inability to lie on their side
  • Vertebral deformities were ascertained from lateral spine scans between T4-5 to L4-5 vertebrae using the instant vertebral fracture assessment function of the DXA scanner; diagnosed by two scientists “experienced in diagnosing vertebral abnormalities” who assessed the scans “visually and semi-quantitatively”
    • 20% or greater reduction in height of the anterior or mid portion of a vertebral body relative to the posterior heights of that body;
    • Or a minimum 20% reduction in any of the these heights compared with the vertebral body above or below the affected vertebral body
  • Fracture history
    • Baseline interview; used if occurred in the preceding 10 years
    • Three observers independently rated fractures using the description of mechanism of injury
    • Claimed high level of agreement between observers (measured); procedure if disagreement not described
  • Statistical analysis restricted to only the 1626 men who completed all DXA scans

Results summary:

  • Of the 1625 completing all DXA scans, 401 (25%) met the PBS criteria for osteoporosis treatment
    • 90% of these men were unaware that they had osteoporosis
    • of these men, 39 (10%) were reported using a bisphosphonate
    • however, only 3 (1%) received a bisphosphonate with calcium and vitamin D
  • However, only 82 (5%) men had a minimal trauma fracture (20% of the group who met PBS criteria for bisphosphonates)
  • Only 13% of these men received bisphosphonate therapy

Study conclusion:

Despite a high prevalence of osteoporosis in elderly Australian men, awareness, diagnosis and treatment of the condition remain very low.


Participants:

  • Of 2815 men invited, only 1511 participated with an additional 194 self referred.
  • Of those unable to complete all the necessary scans, the largest number were those who have had bilaterally hip replacements and those who were unable to lie on their side
  • There appeared to be a good number of men in ages from 70 to 89 but few who were over 90 years.
  • There is little else reported in terms of the demographic data (though a reference is given claiming that the men were representative of men in the study area in terms of age and ethnicity and it was claimed that they were similar in characteristics to older men in the MATeS study).

Methodological weaknesses

  • There is a serious issue with participant recruitment though it may not invalidate the conclusion.  It is probable that men in this study are not a representative sample of the eligible community population:
    • The cohort of men who chose to participate on the invitation and those who self referred are likely healthier than the men who did not participate.
    • The men who were able to complete all scans and thus be included in the statistical analysis are likely healthier than the men who could not complete the scans.
    • As such, it is probable that the study underestimates the burden of osteoporosis in the community population, or, that the osteoporosis in the study participants is more likely to have been of lower morbidity.
    • Moreover, it is also likely that the study similarly underestimates the rate of osteoporosis diagnosis and treatment in the community.  There are questions on the external validity of the results.
    • It does seem probable, nevertheless, that the magnitude of detected underdiagnosis and undertreatment reflects a true level of underdiagnosis and undertreatment.
  • The use of instant vertebral fracture assessment with the DXA machine is not the gold standard in diagnosing vertebral fractures and may have lead to a small degree of underdiagnosis.
    • It is unlikely that this would have substantially changed the study conclusion it itself barring an undetected systematic error.
  • A third weakness (in interpreting the results from a primary health care perspective) is that the authors did not measure (or if so, did not report) the prevalence of known osteoporosis risk factors such as loss of height, low BMI, hypogonadism, glucocorticoid use, hyperthyroidism, etc.  As such the true “missed opportunity” of diagnosis in the primary health care setting is unknown.  Admittedly, this was not a research aim of the study.
    • Only 5% of the participants (20% of the group meeting PBS criteria for bisphosphonates) had suffered from a low impact fracture
    • BMD screening is only recommended for those considered at “high risk” of osteoporosis [2], and argued by some, not at all [3].
    • Without any further information, even assuming perfect compliance with the RACGP preventive guidelines and perfect diagnosis, only 5% of the participants should have known that they had osteoporosis and were suitable for treatment as DXA evaluation would not have been indicated.

Methodological strengths

  • Large cohort of men including good numbers of older men.
  • Demonstration of high prevalence and low treatment rate of osteoporosis in men.

Biases and conflicts of interests

  • Seibel M (fourth author) is declared as a member on advisory boards for Merck Sharp and Dohme, Novartis, Amgen and Sanofi-Aventis and has received funding from these companies for institutional research.
  • Sambrook P (fifth author) is declared as a member of advisory boards for Merck Sharp and Dohme, Novartis, Amgen, Sanofi-Aventis and Servier and has received speaker fees from these companies.
  • Undeclared: the study implicitly supports increased testing of BMD (for example, the emphasis on vertebral fracture assessment with DXA in the article discussion as the diagnostic modality for diagnosis vertebral body fractures rather than a radiograph [1]) which is of direct benefit to osteoporosis researchers and medical specialists treating osteoporosis.

Clinical relevance to primary health care

Of greatest practical concern to general practitioners, it appeared that only 13% of the men who historically had suffered a minimal trauma fracture (arguably those who can be diagnosed most easily, are at high risk, and benefit the most from treatment) had received bisphosphonates.  What is unreported and likely unknown is the proportion of these men who were aware of the diagnosis of osteoporosis, and the proportion their general practitioners were aware.  In the absence of this information, one can only speculate at the true rates of underdiagnosis and undertreatment in the primary health care setting, even if we disregard the effects of the potential bias introduced by the recruitment procedure.

The second practical point for general practitioners is the almost complete absence of concurrent use of calcium and vitamin D in the participants taking bisphosphonates.  We should be reminded that studies on the use of bisphosphonates for osteoporosis include the co-administration of both oral calcium and vitamin D supplements.

This study demonstrates the high prevalence, and probable low diagnosis and low treatment rates of osteoporosis in older men.  Considerable uncertainty remains surrounding the use of BMD for osteoporosis screening due to its low predictive value for fractures for the individual [3] as well as the unlikelihood that population level treatment of osteoporosis will be cost-effective.  Until there is more definitive evidence, it would be prudent to follow the RACGP guidelines for osteoporosis [2] which only involves the use of BMD in individuals considered at high risk.

References

  1. Bleicher K, Naganathan V, Cumming RG, et al. Prevalence and treatment of osteoporosis in older Australian men: findings from the CHAMP study. MJA 2010;193:387-391
  2. Osteoporosis (Ch. 14) in Guidelines for preventive activities in general practice, 7th edition. Royal Australian College of General Practitioners, April 2009
  3. Wilkin T, Devendra D. Bone densitometry is not a good predictor of hip fracture.  BMJ 2001;323:795–9
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