Structuring complexity of testing: a process oriented approach to limiting unnecessary laboratory use.

The concept of structuring complexity is described as a process in which, during medical investigation, intensity of laboratory examination is escalated as the perceived complexity of diagnostic need increases. Application of this concept to laboratory controlled testing protocols is discussed. A clinical chemistry protocol for thyroid testing of ambulatory care patients in British Columbia resulted in a 15% reduction in test use and a 12% reduction in laboratory charges to the third party paying agent over a two-year period. The need to develop medically acceptable laboratory protocols that encourage selective test utilization and reduce cost is emphasized.

Laboratory costs and utilization: a framework for analysis and policy design.

A conceptual framework is outlined as the basis for analysis and evaluation of laboratory test-ordering patterns. This framework highlights the input, process, and output phases of the laboratory inquiry system. Data are presented from a contemporary Canadian study to show that the cost of laboratory testing is escalating and represents a sizable proportion of hospital costs. Practical policy interventions intent on reducing the costs in this complex system will require thorough analysis within a conceptual framework such as is outlined here and will require ultimately sophisticated control programs at various levels in the laboratory inquiry system.

Membranoproliferative glomerulonephritis type 1: comparison of natural history in children and adults.

Clinical, laboratory and pathological data on 46 patients (29 children and 17 adult) with Type 1 membranoproliferative glomerulonephritis (MPGN) were reviewed in order to compare the natural history of the disease in two age groups. The nephrotic syndrome was the most common presenting clinical feature in both age groups. Established renal failure at time of biopsy was seen in adult males only. All the adults males, but none of the women, were either dead or in renal failure after a mean duration of diseases of 17.7 months. In contrast 43% of the children (both sexes) were in renal failure after a mean duration of disease of 51.6 months. Statistical analysis disclosed that only up to 48 months was there a significant difference in survival between the two age groups (P less than .01). Beyond this time the difference was not statistically significant. The difference in behaviour of MPGN in the two age groups is similar to that observed in other glomerulonephropathies.

Goodpasture's syndrome: diagnosis by transbronchial lung biopsy.

A 28-year-old man developed recurrent hemoptyses, breathlessness, anemia, and bilateral pulmonary infiltrates after mild smoke inhalation. He had no laboratory evidence of kidney involvement. Transbronchial lung biopsy showed erythrocytes, iron-containing macrophages within alveolar spaces, normal basement membranes, and strongly positive linear staining of alveolar septa for immunoglobulin G (IgG). Serum antiglomerular basement-membrane antibody was strongly positive by radioimmunoassay. Kidney biopsy showed normal findings by light and electron microscopy but strongly positive linear staining of glomerular capillaries for IgG. Follow-up 9 months later while the patient was taking prednisone revealed no clinical evidence of pulmonary or renal disease. This case shows that immunopathologic study of transbronchial lung biopsies is helpful in differentiating between Goodpasture's syndrome and idiopathic pulmonary hemosiderosis, while the absence of clinical and microscopic evidence of kidney disease does not exclude Goodpasture's syndrome.

Familial juvenile nephronophthisis. Experience with eleven cases.

Familial juvenile nephronophthisis (FJN) has an incidence in British Columbia of 1 per 50000 live births which gives a heterozygote frequency of 1 per 115. The authors report six families with a total of 11 cases. Multiple affected sibs are described in three families and in no instance was the condition present in more than one generation. The inheritance pattern is consistant with an autosomal recessive trait. The characteristic features are polyuria and azotemia though the presenting features may be either anemia or growth retardation with polyuria being elicited in the functional inquiry. There is a very hypotonic urine and absence of urinary sediment. Decreasing renal function at a variable rate is the fate of these patients, three of whom have had cadaver transplants.

Glomerulonephritis: a review based on 52 renal biopsies.

The pathological findings in 52 renal biopsies are described, with emphasis on the changes seen in glomerulonephritis. There were 12 cases of poststreptococcal glomerulonephritis, eight of idiopathic membranous glomerulonephritis, and 10 of lipoid nephrosis. Poststreptococcal glomerulonephritis is subdivided into acute and persistent phases, and the latter is further defined as subacute, latent or chronic. The characteristic but not specific lesion of post-streptococcal glomerulonephritis is the development of mesangial scars. In lipoid nephrosis there are subendothelial deposits in the glomerulus. Membranous glomerulonephritis is characterized by massive heterogeneous deposits on the outside surface of the basement membrane. It is concluded that there are three well-defined types of glomerulonephritis, and although future studies may reveal interrelationships, the clinical and pathological evidence to date is sufficient to warrant their separate classification.