Ronald E. Thomas

Functional Independence Score in Haemophilia: a new performance-based instrument to measure disability

Summary.  Morbidity in haemophilia has been described predominantly in terms of musculoskeletal dysfunction and assessed by the clinical and radiological joint scores. These scores document changes in a particular joint, but do not reflect the impact of these changes on the individual in terms of his overall musculoskeletal function. Several self‐assessment instruments have been used to measure musculoskeletal function but none have been specifically validated for use in haemophilia. In order to objectively assess musculoskeletal function of patients with haemophilia, we developed Functional Independence Score in Hemophilia (FISH), a performance‐based instrument. FISH measures the patients independence in performing seven activities under three categories: self‐care (grooming and eating, bathing and dressing), transfers (chair and floor) and mobility (walking and step climbing). Each function is graded from 1 to 4 depending on the amount of assistance needed in performing the function. We evaluated 35 patients who were over 10 years old and had had at least three major bleeds per year. All subjects were scored for clinical (World Federation of Hemophilia, WFH score) and radiological changes (Petterssons score). Functional independence of the patient was assessed using the Stanford Health Assessment Questionnaire (HAQ) and the FISH. Correlation of the FISH score was modest with both the WFH clinical score (r = −0.68) and the radiological score (r = −0.44). While there was good correlation between FISH and HAQ (r = −0.90), FISH had better internal consistency than HAQ (Cronbachs α 0.83 vs. 0.66). FISH appears to be a promising disease‐specific instrument for assessing overall musculoskeletal function in haemophilia. It requires evaluation in different patient populations.

Dose and outcome of care in haemophilia – how do we define cost-effectiveness?

Summary.  Severe haemophilia (factor [F]VIII/FIX activity < 0.01 IU mL−1) is characterized by repeated haemarthroses resulting in severe arthropathy in adulthood. In 1958, Professor Nilsson in Sweden introduced prophylactic infusions with clotting factor concentrates at regular intervals in order to maintain clotting factor levels above 0.01 IU mL−1 and to prevent bleeding. Since then, evidence of the long‐term beneficial effects of prophylactic treatment for severe haemophilia has been increasing and it has become the recommended treatment strategy for children with severe haemophilia by both the World Health Organization and the US National Hemophilia Foundation Medical and Scientific Advisory Committee. However, the implementation of this recommendation has been hampered by issues of cost and venous access. The high costs of prophylaxis have largely prevented its use in major parts of the world. The question therefore is whether the current models of replacement of clotting factor concentrates, while certainly being effective, are also optimal. Can the data on outcome at different levels of factor replacement be used to assess their cost‐effectiveness?

Progression of damage caused by temperature cycling on a large die in a molded plastic package

Large silicon chips in molded plastic packages suffer physical damage to top-surface regions when subjected to repetitive thermal excursions. It is shown that a delamination between the molding compound and the die surface, progressing inward from a crack in the molding compound at a die corner, can enter an aluminum film through a crack in the passivation glass at an edge, travel through the metal, and exit at the opposite edge. This permits migration of glass and metal inward from corner regions. It is pointed out that reduced susceptibility to this effect may be obtained through the use of tougher metal, thicker passivation glass in lower metal edge corners, and tougher glass. A silicon integrated circuit chip approximately 250*290 mils in a 52-lead PLCC (plastic leaded chip carrier) was used as a test vehicle. Temperature and thermal shock cycling, from as low as -65 degrees C to +150 degrees C and for as many as 2000 cycles was performed.<<ETX>>