Validation of administrative data case definitions for gestational diabetes mellitus.

AIM: To examine, using administrative data, the validity of two algorithms for identifying gestational diabetes mellitus: 1) the current National Diabetes Surveillance System algorithm for excluding gestational diabetes cases and 2) gestational diabetes-specific ICD codes in the delivery-related hospitalization. METHODS: This was a retrospective study of all women, aged 18-54 years, residing in Alberta, Canada, with singleton deliveries between 1 April 1999 and 31 March 2010. We linked Alberta Perinatal Health Program data on all deliveries to administrative claims data from Alberta Health using the mother's personal health number. For both gestational diabetes algorithms, we calculated the sensitivity, specificity, positive predictive value, negative predictive value and agreement, using gestational diabetes identified in the Alberta Perinatal Health Program as the 'gold standard'. RESULTS: Our study sample consisted of 411 390 deliveries for 273 152 women. The mean (sd) age was 29.1 (5.6) years and 82.3% of the women were white. Crude rates of gestational diabetes were 3.9% (16 215 cases), 1.3% (5189 cases) and 4.0% (16 440 cases) according to the Alberta Perinatal Health Program, National Diabetes Surveillance System and ICD code-based algorithms, respectively. Compared with the Alberta Perinatal Health Program database, the National Diabetes Surveillance System algorithm had a sensitivity of 25% and specificity of 100%, whereas the gestational diabetes-specific ICD code-based algorithm had a sensitivity of 86% and specificity of 99%. CONCLUSIONS: The National Diabetes Surveillance System algorithm underestimates the number of gestational diabetes cases. A more valid mechanism to identify gestational diabetes prevalence using health administrative data is the use of gestational diabetes-specific ICD-9/10 codes in the delivery hospitalization.

Efficacy of topical povidone-iodine during the first week after ophthalmic surgery.

PURPOSE: In the first postoperative day, povidone-iodine ophthalmic solution prevents an increase in conjunctival bacterial colony-forming units and decreases the species compared with antibiotic. We sought to determine whether these beneficial effects of povidone-iodine could be sustained during the first postoperative week. METHODS: In 42 eyes of 35 consecutive patients, one or two drops of either a broad-spectrum antibiotic (polymyxin B sulfate-neomycin sulfate-gramicidin) or povidone-iodine 1.25% to 2.5% were placed in the treated eye or eyes at the conclusion of surgery and three times daily during the first postoperative week. Bacterial cultures were taken from both eyes at the end of surgery before instillation of either of the eyedrops and again 1 week later. Twenty-eight untreated eyes served as a control group. RESULTS: During the first postoperative week, the number of colony-forming units and species increased in both treatment groups. Relative to the control group, both medications effectively reduced the mean number of colony-forming units at 1 week (P < .02), but their effects on colony-forming units did not significantly differ from each other (80 +/- 290 for the povidone-iodine-treated eyes and 75 +/- 90 for the antibiotic-treated eyes). At 1 week, the species count increased 281% in the antibiotic group but only 106% in the povidone-iodine group. Compared to the control group, eyes that received povidone-iodine had a significantly lower species count (P = .0097). CONCLUSION: Povidone-iodine ophthalmic solution is an alternative to postoperative topical antibiotics because of its effectiveness in controlling conjunctival bacterial colony-forming units and species, its relatively low cost, and its availability.

Fidelity studies of the human DNA polymerase alpha. The most conserved region among alpha-like DNA polymerases is responsible for metal-induced infidelity in DNA synthesis.

Mutational studies in the highly conserved region I domain of the human DNA polymerase alpha enzyme demonstrated a change in metal cation-specific catalysis. Here, we extend the investigation to include the fidelity of DNA synthesis by these mutants, studying misinsertion, mispair extension, and the nucleotide analog utilization. The fidelity of region I mutants and wild type human DNA polymerase alpha enzyme were analyzed with either Mg2+ or Mn2+ as the metal activator. Despite the known mutagenic effect of Mn2+ in causing polymerases to misinsert nucleotides and to utilize dideoxynucleotides, we have found that two region I mutants, D1002N and T1003S, which utilize Mn2+ in catalysis more effectively than Mg2+, actually have a 70- and 40-fold higher misinsertion fidelity, respectively, in Mn(2+)-catalyzed reactions than that of the wild type enzyme. The enhanced misinsertion fidelity of these two mutants in Mn(2+)-catalyzed reactions is due to Km discrimination of the incorrect nucleotide where the D1002N and T1003S had a 850- and 62-fold higher Km for insertion of incorrect than correct nucleotide, respectively. In Mg(2+)-catalyzed reactions, all of the region I mutants exhibited similar misinsertion efficiencies as the wild type polymerase. Study of mispair extension showed that in Mn(2+)-catalyzed ractions, the wild type polymerase alpha enzyme readily extended mispair termini. In contrast, the two region I mutants, D1002N and T1003S, were unable to extend the mispaired termini in either Mg(2+)- or Mn(2+)-catalyzed reactions. These results suggest that the side chains of region I amino acids play an essential role in the Mn(2+)-induced infidelity during DNA synthesis by human DNA polymerase alpha. The effects of the metal activator on the utilization of two nucleotide analogs, 3'-azido-3'-deoxythymidine triphosphate and ddCTP, by the region I mutants were also investigated.