Impact of chondroitin sulphate on health utility in patients with knee osteoarthritis: towards economic analysis

OBJECTIVES

The first objective was to assess the effect of the chondroitin 4 and 6 sulphate (CS) on health-related quality of life using utility values in patients with knee osteoarthritis (OA) during a 24-month treatment course. The second objective was, using these data, to conduct economic analyses.

METHODS

Data from the STOPP study was used. This study was a randomised, double-blind, placebo (PL) -controlled trial of 2-year duration. In the STOPP study, authors assessed quality of life using the Western Ontario and McMaster Osteoarthritis Index (WOMAC). WOMAC scores were translated into Health Utility Index (HUI) scores using a specific formula. Incremental cost effectiveness ratio (ICER) was calculated taking into account the cost of CS and its effect on HUI scores, compared to PL.

RESULTS

At baseline, the mean (SD) HUI scores were 0.59 (0.17), and 0.59 (0.18) for the PL and CS groups, respectively (p=0.31 between the two groups). The mean (SD) HUI scores changes from baseline to 6 months were 0.02 (0.02), and 0.05 (0.01) for the PL and CS groups, respectively (p=0.03). After 24 months of follow-up, HUI score increases by 0.04 (0.02) in the PL group and by 0.05 (0.02) in the CS group (p=0.37). Using the price bracket of CS in Europe, ICER assessment always resulted in a cost below €30,000 per QALY gained, after 6, 12 and 24 months of treatment.

CONCLUSION

CS treatment increases health utilities in patients with knee OA compared to PL over the first 6 months of treatment. Economic evaluation based on these data suggests that CS treatment could be considered as cost-effective in patients with knee OA up to a period of 24 months. A limitation in this study is the absence of direct utility assessment as well as the absence of effective treatment as comparator.

Identification of the Origin of Chondroitin Sulfate in "Health Foods"

Twelve "health foods" products containing chondroitin sulfate (CS) were purchased from the Japanese market and the origin of the CS was investigated by conducting disaccharide compositional analysis after enzymatic depolymerization and by 1H-NMR spectroscopy. Nine of the 12 products had labels indicating that the origin of the CS was shark cartilage. However, two of them were found to contain mammalian CS. Next, we compared the ratio of the sulfate group to the galactosamine residue after the acid hydrolysis of CS. The results suggest that all of the CS from sharks had a ratio of more than 1.0, while the CS from mammals had a ratio of less than 1.0. Since this comparative analysis does not require expensive purified enzyme, it would be an economical way to identify the origin of CS in "health foods." Being able to determine the origin of the ingredients in natural products is very important for ensuring their quality, safety, and efficacy. Therefore, we think that regulatory requirements for accurately indicating the origin of "health foods" and effective enforcement of these requirements are needed.

Chondroitin sulfate for interstitial cystitis

(1) Chondroitin sulfate solution 2.0% is a glycosaminoglycan (GAG) replenishment therapy instilled into the bladder of GAG-deficient patients with interstitial cystitis (IC). (2) Two non-randomized, uncontrolled pilot studies report improvements in patient-reported symptoms after the use of chondroitin sulfate for one year. Prospective, randomized, head-to-head trials are needed to assess the effectiveness of this technology compared with other IC therapies. (3) The cost and demand for this technology are low, but there could be a significant impact on clinics that administer treatment, if uptake increases.

[Pharmacoeconomic aspects of use of structum in osteoarthrosis]

AIM

To study cost-effect efficiency of structum in patients with knee and hip joint osteoarthrosis (OA) in a multicenter trial.

MATERIAL AND METHODS

The trial enrolled 192 patients with OA. 110 patients had knee joint OA and 82 patients hip joint OA. The patients received structum for 6 months. Efficacy of the treatment was assessed before use of structum and after it by standard methods. Integral effect of therapy was estimated according to the special program complex. The cost of the drug therapy included the cost of structum and nonsteroid anti-inflammatory drugs (NSAID) on conversion to 1 mg of diclofenac plus the cost of treating side effects. The efficacy per unit cost was calculated by the formula: E1xC2/E2xC1, where E1--integral efficacy of therapy before using structum, E2--integral efficacy of therapy in administration of structum, C1--cost of drug therapy, C2--cost of drug therapy in using structum.

RESULTS

E2 was equal to 94% for knee joints OA and 92% for hip joint OA, E1 and C1--21 and 19%, respectively. C2 was equal to 108.43$ for knee joint OA and 106.97 for hip joint OA, C1--29.3 and 27.44, respectively. The efficacy per unit cost for knee joint OA was 94 x 29.3/21 x 108.3 = 1.21, for hip joint OA 92 x 27.44/19 x 106.97 = 1.24. The figures evidence for much higher efficacy per unit cost of structum vs routine NSAID.

CONCLUSION

The multicenter trial gave grounds not only for clinical efficacy of structum vs NSAID but also for cost-effect advantage of structum in therapy of OA.

Danaparoid sodium

Danaparoid sodium (Orgaran, Organon) is a heparinoid glycosamino-glycuronan antithrombotic agent approved for the prophylaxis of post-operative deep vein thrombosis (DVT), which may lead to pulmonary embolism (PE) in patients undergoing elective hip replacement surgery. Danaparoid is a low molecular weight heparinoid consisting of a mixture of heparan sulphate (84%), dermatan sulphate (12%) and small amounts of chondroitin sulphate (4%), whose antithrombotic activity has been well established. Its pharmacological effect is exerted primarily by inhibiting Factors Xa (FXa) and IIa (FIIa) at a ratio greater than heparin, with a minimal effect on platelet function. Danaparoid exhibits low cross-reactivity with heparin-induced antibodies when compared with heparin or low molecular weight heparins (LMWH), thereby making it an excellent choice for the management of heparin-induced thrombocytopenia (HIT). It has excellent bioavailability following s.c. injection. Danaparoid has little effect on routine coagulation tests (activated partial thromboplastin time [aPTT], prothrombin time [PT], and thrombin time [TT]). Patients with elevated serum creatinine should be monitored carefully. For its FDA approved indication (DVT prophylaxis during hip replacement surgery), its cost per day is approximately eight times more than LMWH. Even though monitoring is not routinely necessary according to the manufacturer for its approved indication, monitoring is frequently necessary when it is used in other clinical scenarios. Its higher cost than comparable therapies for DVT prophylaxis and the low availability of the FXa assay in most non-tertiary care hospitals has limited the widespread use of danaparoid. Danaparoid has been found to be effective in the treatment of HIT although this is an off label use, despite being the most frequent reason why danaparoid is used.

[Chondroitin sulfates (CS 4&6): practical applications and economic impact]

PROVEN CLINICAL BENEFIT: It has been demonstrated that CS 4&6 administered at the dose of 1200 mg/d for several months is more effective than placebo and as effective as nonsteroidal anti-inflammatory drugs (NSAID) in providing pain relief and improving joint function without risk in subjects with osteoarthritis of the hip and the knee. The beneficial effect persists several weeks after the end of treatment. These advantages should thus have an overall cost-lowering effect. EVALUATION OF THE ECONOMIC IMPACT: A medico-economical study was conducted to reevaluate the beneficial effect of CS 4&6 on the quantity of NSAID prescriptions in France and to determine whether the drug was used correctly in accordance with indications at an adequate dose and treatment duration.

DATABASES USED

Two databases, IMS a data bank on medical prescriptions in France, and THALES which gives information on prescriptions by 300 general practitioners, allowed a dynamic analysis of the medical files of 11,000 patients with osteoarthritis. ECONOMICAL BENEFIT: The cost of NSAID prescriptions by general practitioners was reduced by an estimated 67% in patients treated with CS 4&6. In terms of the quantity of NSAID used, the reduction in the CS 4&6 treated group was 63% and 85.3% respectively in patients treated by generalists and by specialists. The quantity of NSAIDs prescribed was reduced by two-thirds when CS 4&6 were represcribed. The cost related to CS 4&6 treatment was compensated for by the reduction in physiotherapy costs and by fewer co-prescriptions for gastroprotective drugs. This study confirmed the randomized clinical studies demonstrating that a regimen of CS 4&6 for several weeks at the dose of 1200 mg/d lowers prescriptions of NSAID which can be completely avoided in nearly half the cases.