Cost-effectiveness of using continuous positive airway pressure in the treatment of severe obstructive sleep apnoea/hypopnoea syndrome in the UK.

OBJECTIVE: A study was undertaken to estimate the cost-effectiveness of using continuous positive airway pressure (CPAP) in the management of patients with severe obstructive sleep apnoea/hypopnoea syndrome (OSAHS) compared with no treatment from the perspective of the UK's National Health Service (NHS). METHODS: A Markov model was constructed to assess the cost-effectiveness of CPAP compared with no treatment. The model depicted the management of a 55-year-old patient with severe OSAHS as defined by an apnoea-hypopnoea index (AHI) >30 and daytime sleepiness (Epworth Sleepiness Scale score >or=12). The model spans a period of 14 years. RESULTS: According to the model, 57% of untreated patients are expected to be alive at the end of 14 years compared with 72% of patients treated with CPAP. Untreated patients are expected to cost the NHS pound10 645 (95% CI pound7988 to pound14,098) per patient over 14 years compared with pound9672 (95% CI pound8057 to pound12,860) per CPAP-treated patient. Treatment with CPAP for a period of 1 year was found not to be a cost-effective option since the cost per quality-adjusted life year (QALY) gained is expected to be > pound20,000, but after 2 years of treatment the cost per QALY gained is expected to be pound10,000 or less and, after 13 years of treatment, CPAP becomes a dominant treatment (ie, more effective than no treatment for less cost). CONCLUSION: Within the limitations of the model, CPAP was found to be clinically more effective than no treatment and, from the perspective of the UK's NHS, a cost-effective strategy after a minimum of 2 years of treatment.

Renal pathology in adults over 40 with sickle-cell disease

In a retrospective study of hospital necropsies, we examined the kidneys of 21 patients with homozygous sickle-cell disease who died at the age of 40 or over. Renal failure had caused or contributed to death in ten cases. All kidneys showed changes of papillary damage to a variable extent. In three cases, there was mild cortical irregularity, and in thirteen, there was moderate to severe cortical irregularity, including scarring in some with obvious loss of functioning tissue. Light microscopic examination revealed hypertrophic glomeruli with increased cellularity, lobulation and capilary basement membrane splitting. Glomerulosclerosis was common, and patchy deposits of fibrin were present in glomerular capilaries in complex glomerulonephritis, we suggest that sclerosis consequent upon longstanding hyperfiltration may be more important. Glomerular filtration rate is abnormally high in children with sickle-cell disease but in later childhood renal insufficiency, proteinuria and eventually death from renal failure become common