Hospital admissions for dental treatment among children with cleft lip and/or palate born between 1997 and 2003: an analysis of Hospital Episode Statistics in England.

BACKGROUND: Children with clefts have an increased tendency for dental anomalies and caries. AIM: To determine the pattern of hospital admissions for dental treatment during primary dentition among children with clefts. DESIGN: Cohort study based on Hospital Episode Statistics, an administrative database of all admissions to National Health Service hospitals in England. Patients born alive between 1997 and 2003 who had both a cleft diagnosis and cleft repair were included. The number of hospital admissions for surgical removal of teeth, simple extraction of teeth, and restoration of teeth before the age of seven was examined. RESULTS: Eight hundred and fifty-eight hospital admissions for dental treatment among 6551 children (<7 year) with a cleft were identified. 66.4% of admissions were primarily for caries and 95.6% involved extractions. 11.4% of children had at least one admission for dental treatment. The presence of additional anomalies, having a more severe cleft type, and living in relatively deprived areas increased the risk of hospital admission. CONCLUSIONS: Factors increasing the risk of hospital admission among cleft children should be taken into account when planning services. Efforts to reduce the number of hospital admissions should be focused on disease prevention, particularly among those most at risk of caries.

Cemented, cementless, and hybrid prostheses for total hip replacement: cost effectiveness analysis.

OBJECTIVE: To compare the cost effectiveness of the three most commonly chosen types of prosthesis for total hip replacement. DESIGN: Lifetime cost effectiveness model with parameters estimated from individual patient data obtained from three large national databases. SETTING: English National Health Service. PARTICIPANTS: Adults aged 55 to 84 undergoing primary total hip replacement for osteoarthritis. INTERVENTIONS: Total hip replacement using either cemented, cementless, or hybrid prostheses. MAIN OUTCOME MEASURES: Cost (£), quality of life (EQ-5D-3L, where 0 represents death and 1 perfect health), quality adjusted life years (QALYs), incremental cost effectiveness ratios, and the probability that each prosthesis type is the most cost effective at alternative thresholds of willingness to pay for a QALY gain. RESULTS: Lifetime costs were generally lowest with cemented prostheses, and postoperative quality of life and lifetime QALYs were highest with hybrid prostheses. For example, in women aged 70 mean costs were £6900 ($11 000; €8200) for cemented prostheses, £7800 for cementless prostheses, and £7500 for hybrid prostheses; mean postoperative EQ-5D scores were 0.78, 0.80, and 0.81, and the corresponding lifetime QALYs were 9.0, 9.2, and 9.3 years. The incremental cost per QALY for hybrid compared with cemented prostheses was £2500. If the threshold willingness to pay for a QALY gain exceeded £10 000, the probability that hybrid prostheses were most cost effective was about 70%. Hybrid prostheses have the highest probability of being the most cost effective in all subgroups, except in women aged 80, where cemented prostheses were most cost effective. CONCLUSIONS: Cemented prostheses were the least costly type for total hip replacement, but for most patient groups hybrid prostheses were the most cost effective. Cementless prostheses did not provide sufficient improvement in health outcomes to justify their additional costs.

Continuous monitoring of long-term outcomes with application to hip prostheses.

The CUSUM continuous monitoring method could be a valuable tool in evaluating the performance (revision experience) of prostheses used in hip replacement surgery. The dilemma when applying the CUSUM in this context is the choice of statistical model for the outcome (revision). The Bernoulli model is perhaps the most straightforward approach but the Poisson model is a plausible, and could be argued, preferable alternative for long-term outcomes such as this, provided the rate of revision with time from surgery can be assumed to be constant. However, a rate (or hazard) varying according to the Weibull distribution appears to be a better representation of a prosthesis lifetime. We show how to adapt the Poisson approach to allow for the hazard to vary according to the Weibull model as well as other parametric survival models. Application to data on a known poorly performing prosthesis shows both the Poisson and Weibull CUSUMs could have given early warning of the poor performance, with the Weibull chart alerting before the Poisson. Simulation work to investigate the robustness of the Poisson and Weibull CUSUM to departures from the underlying survival model highlights the need for correct specification of the model for the outcome.