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A Loría

Publications and source records attributed to A Loría.

At least 55 records · Page 3Linked to original sources
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[The pilot program in Mexican clinical laboratories. I. The characterization of structure and productivity].

OBJECTIVE: To validate a questionnaire which evaluates the structure of clinical laboratories and to obtain information on its productivity. PARTICIPANTS: A group of 18 laboratories belonging to hospitals of second (N = 15) and third (N = 3) levels of health care. Fifteen participants belong to the public sector and three are first rate private institutions. They are located in the metropolitan area of Mexico City comprising the Federal District (N = 12) and the State of Mexico (N = 6). METHODS: The questionnaire has 12 items which received a 0, 1/2 or 1 score. The maximum possible score for a perfect laboratory as well as for any question is 100. The questionnaire was filled during a visit to the participating hospitals by auditors of the agency of the Ministry of Health in charge of licensing laboratories at a national level. Information covering six months of work was obtained to calculate productivity using number of tests per worker per month. RESULTS: The global score of the 18 participants was 49. The private ones had the highest scores (79 to 96) which was to be expected as they were selected for their high technical and human resources. The five State laboratories had a score above the global mean, but only one of the Federal ones was in this situation. A high interlaboratory variability was observed, i.e. productivity in the highest rated was nine times larger than in the lowest rated. This finding suggests the presence of interlaboratory differences in the criteria used in the collection of productivity information. CONCLUSIONS: This short questionnaire can be used as a first approximation to identify structure deficiencies of the Mexican clinical laboratories.

Efficiency, Organizational↗
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[The pilot program in Mexican clinical laboratories. II. The characterization of the operating processes].

OBJECTIVE: To evaluate a questionnaire for operating procedures in Mexican clinical laboratories. PARTICIPANTS: A group of 18 hospital laboratories (described in the first paper of this series). METHODS: The questionnaire had 132 items exploring nine sections (bacteriology, clinical chemistry, general hematology, immunology, microbacteriology, mycology, parasitology and urine analysis) and it was filled by the participants and modified if necessary in an audit visit. The questions were scored in the range of zero to one, and the participants in a scale of zero to 100 points. RESULTS: the answers had scores ranging from zero (N = 3) to one (N = 11) and a distribution with a clear shift to high scores. This led to a partition in three categories (low: < 0.3, medium: 03.-0.7, high: > 0.7) and to calculate a low/high ratio which enabled us to identify poor procedures in the sections. This ratio was also used to evaluate the type of procedure involved, i.e. management (N = 51), resources (N = 36), quality control (N = 23), and type and number of tests performed (N = 16). In the evaluation of the laboratories, the global score was 60. As expected, the private laboratories had the highest scores (73 to 84) as they were chosen because of their good resources. In the public ones only the State laboratories had more members above the mean score than below, whereas most of the Federal laboratories were below the global mean. CONCLUSIONS: The questionnaire performed reasonably well in spite of some deficiencies, i.e. it should include more questions on the specialized sections and on procedures other than management. The specialized sections (immunology, microbacteriology, mycology and parasitology) had lower scores than the more traditional ones (chemistry, hematology and bacteriology). Resources and quality control had lower scores than management; and the laboratory scores of the auditors tended to be lower than the autoevaluation of the public hospitals.

Laboratories, Hospital↗
PubMedDate not supplied

[The pilot program in Mexican clinical laboratories. III. The strategy for evaluating the quality of the results].

OBJECTIVE: To explore the validity of a simple and rapid strategy which discriminates precision and accuracy of assays done in sera. PARTICIPANTS: The same group of 18 laboratories. METHODS: The sera and results of glucose, urea, creatinine and urates assayed in the routine work of a single day were collected by auditors of an agency of the Ministry of Health. Six laboratories used autoanalyzers and 12 manual kits in the assays. The sera were transported that same day (stored in ice) to a reference laboratory (REF LAB) to repeat the assays as soon as possible. The REF LAB used a spectrum analyzer which showed, throughout the seven months of the study, excellent precision in its internal program and good accuracy in the international EQA program of the World Health Organization. STRATEGY OF ANALYSIS: Precision and accuracy were independently evaluated with two correlates per analyte and participant: the coefficient of correlation of paired results (REF LAB/participant) as a correlate of precision, and the mean of ratios of paired results (participant/REF LAB) as a correlate of accuracy. A correlation below 0.70 and a mean ratio outside of 1 +/- 0.15 were considered inadequate. RESULTS: only 62 systems had information (10 either lacked reagents or had no samples that day). Imprecision was observed in only 8 per cent of the analytes (5/62) which is lower than the 30 per cent usually seen in Mexican EQA programs. On the contrary, the frequency of inaccuracy was high, i.e. the ratios were inadequate in 44 per cent of the systems (28/62). CONCLUSIONS: Our strategy of evaluation was able to discriminate imprecision from inaccuracy. The low frequency of imprecision in the study suggests the possibility of an observer's effect on the observed (date and hour of the audit visit was known in advance). The high rate of inaccuracy highlights the convenience of having a larger local availability of reference materials and EQA programs with reliable control material. The search for indexes discriminating imprecision from inaccuracy should continue for use in laboratories with very little or no experience in EQA.

Humans↗
PubMedDate not supplied

[Increase of conjugated bilirubin in diabetics].

Three hundred patients were studied: 150 had NIDDM and the other 150 were non diabetics. Serum glucose and total and fractionated bilirrubin were measured in samples taken after night fasting. The mean glucose in the NIDDM group was 180.4 +/- 17.9 mg/dL (+/- SD) and 82.7 +/- 4.4 mg/dL in the non diabetic (p < 0.001). The levels of total bilirrubin were similar in both groups (0.84 +/- 0.04 vs 0.81 +/- 0.02 mg/dL, p > 0.40) but there were group differences in direct bilirrubin (NIDDM 0.52 +/- 0.03 vs 0.20 +/- 0.01 mg/dL, p < 0.001) and in indirect bilirrubin (NIDDM 0.32 +/- 0.03 vs 0.61 +/- 0.02 mg/dL, p < 0.001). Thus, 62% of the circulating bilirrubin was conjugated in the diabetics and only 25% in the non diabetics. We believe that at least part of the UDP-glucose pathway is altered in NIDDM and leads to an increase in the levels of glucouronic acid and, in turn, may cause a rise in direct bilirrubin at the expense of indirect bilirrubin.

Adult↗
PubMedDate not supplied

[Permanent clinical chemistry program of the National Institutes of Health. II. Sources of variation in 2 imprecise analyzers].

BACKGROUND: In a previous report of the program of interlaboratory concordancy in the MNIH (Mexican National Institutes of Health) we observed imprecision in nearly half of the analytes assayed by participants B and J. OBJECTIVES: 1. To identify possible sources of variation in the analyzers. 2. To take corrective actions and see their effect on precision. MATERIAL AND METHODS: Analyzer B had been operating for 2.5 years and analyzer J for more than ten years (Lab J switched to a new analyzer from a different supplier in the last three months of the study). Both participants submitted their daily results in commercial controls (normal and high). Lab J furnished results for a period of six months (Jul-Sep/92 using the old analyzer, and Oct-Dec using the new one) and Lab B reported five months (it used Jul to change its operating procedure). Lab B assayed 16 analytes (two electrolytes, four enzymes and ten organic analytes) and Lab J 17 (four electrolytes, four enzymes and nine organic). They also agreed to maintain a logbook of any change in calibrators, controls, reagents, analysts, or operating procedures. The information of the first two months was used in a multiple analysis of variance (MANOVA) using the control assays as the dependent variable, and the logbook notations as the independent variables. Precision was expressed as a monthly mean of means of CVs of all analytes. RESULTS: The MANOVA identified two sources of variation in analyzer B: 1) recalibrations (done fortnightly in an effort to improve performance); 2) control flasks. A restriction of calibrations led to an improvement in precision, i.e. from a CV of 5-7% in Aug-Sep to 3-4% in Oct-Dec. In the old analyzer of Lab J, the MANOVA was unable to identify causes of the high imprecision (CVs of 14-19% in Jul-Sep). With the new analyzer, precision improved (CV of 6% in Nov-Dec). Two observations of interest in the new analyzer were: a) a period of familiarization with the apparatus was apparently needed (CV was 11% in Oct); b) imprecision persisted in three analytes (CVs of 11-14% in BUN, calcium, and triglycerides in Nov-Dec). A second MANOVA in this lapse also failed to identify sources of variation for these three analytes. CONCLUSIONS: 1. Analyzer B is operating at an acceptable level of precision and can fully participate in our program. 2. The new analyzer of J can participate in the assays of 14 analytes.

Academies and Institutes↗