Biomedical subjects

E G Lydick

Publications and source records attributed to E G Lydick.

9 recordsLinked to original sources

PubMed1996

Is school vision screening effective?

A population-based cohort of all children entering kindergarten in a three-year period (N = 2,938) was followed retrospectively from kindergarten through 12th grade to estimate incidence of abnormal school vision screening tests and rates of follow-up by community ophthalmologists or optometrists. Overall 28% of children had at least one abnormal school vision screening test. Abnormal screening with referral increased from 1.2% of five-year-olds to 9.1% of 13-year-olds. Overall, 91% of children referred had further evaluation by eye care professionals. However, visits to an eye care professional often were delayed; median time was 0.8 years for children seeing an ophthalmologist and 1.8 years for children seeing an optometrist. Results support the continued use of simple visual acuity screening in schools. Consideration should be given to screening children beyond age 12 and developing methods to increase the rapidity of parental response to referral recommendations.

Adolescent↗

PubMed1992

Reoperation and mortality after surgical treatment of benign prostatic hypertrophy in a large prepaid medical care program.

The incidence of reoperation and mortality after prostatectomy was studied in 8,219 men who underwent surgical treatment for benign prostatic hypertrophy between 1976 and 1987 while they were members of the Kaiser Permanente Medical Care Program, Northern California Region. The vast majority (94.5%) received transurethral prostatectomy (TURP). The cumulative 8-year probability of a second prostatectomy was 7.6% after TURP and 2.1% after open prostatectomy. The risk of mortality associated with transurethral prostatectomy relative to open prostatectomy was 1.6 (95% confidence interval 1.2, 2.1) 8 years postsurgery. The increased risk of mortality associated with transurethral prostatectomy was most prominent during the first 5 years postsurgery (relative risk 1.8, 95% confidence interval 1.3, 2.5) and declined to 1.1 (95% confidence interval 0.8, 1.6) for deaths occurring after the first 5 years. The finding of an increased risk of mortality associated with transurethral prostatectomy is consistent with other studies and is unexplained.

Aged↗

PubMed1991

Incidence of surgically treated benign prostatic hypertrophy and of prostate cancer among blacks and whites in a prepaid health care plan.

The incidence of surgically treated benign prostatic hypertrophy and of prostate cancer was examined to December 1987 in 14,897 men (2,175 blacks and 12,722 whites) who received multiphasic health checkups during 1971-1972 while members of the Kaiser Permanente Medical Care Program (San Francisco-Oakland, California). Prostate cancer incidence was higher in blacks than in whites for all age groups (age-adjusted relative risk (RR) = 1.8, 95% confidence interval (CI) 1.4-2.3). The incidence of benign prostatic hypertrophy was somewhat higher in blacks than in whites until age 65 years, after which it was higher in whites. In contrast to the risk of prostate cancer, the age-adjusted risk of benign prostatic hypertrophy was the same for blacks as for whites (RR = 1.0, 95% Cl 0.8-1.2).

Adult↗

PubMed1991

Vasectomy and the risk of prostate cancer in a cohort of multiphasic health-checkup examinees: second report.

The relationship of vasectomy to prostate cancer was studied in 5,119 men men with a self-reported history of vasectomy, identified at multiphasic health checkups undergone during 1977-82 while members of the Northern California Kaiser Permanente Medical Care Program. Three unvasectomized comparison subjects were identified for each vasectomized man, matched for age, race, marital status, and date and location of the examination. Follow-up for incident prostate cancer was conducted for a mean length of 6.8 years. The relative risk of prostate cancer associated with vasectomy was 1.0 (95% confidence interval = 0.7 - 1.6); the relative risk was approximately one, regardless of length of interval (less than 10 years, 10-20 years, more than 20 years) between vasectomy and multiphasic health checkup or the age at vasectomy (less than 40 years vs more than 40 years). These data support earlier findings reported in this study group of the lack of an association of vasectomy with subsequent risk of prostate cancer.

Adult↗

PubMed1991

Risk factors for surgically treated benign prostatic hyperplasia in a prepaid health care plan.

The relationship of age, medical history, personal habits, and urologic symptoms to the incidence of surgically treated benign prostatic hyperplasia (BPH) was studied in a cohort of 16,219 men, aged forty years and over, who received multiphasic health checkups (MHCs) during 1971 and 1972 in Oakland or San Francisco while members of the Northern California Kaiser Permanente Medical Care Program, a large prepaid health care program. Follow-up was carried out for surgically treated BPH from the date of the MHC to the date of the earliest of the following: surgery for BPH (n = 1,027); incidence of prostate cancer (n = 329), bladder cancer (n = 119), or both (n = 10); other prostate surgery (n = 5); death (n = 2,525); membership termination (n = 4,235); or December 31, 1987 (n = 7,969). The mean length of follow-up was twelve years. In multivariate analysis utilizing the Cox proportional hazards model, the following characteristics were positively associated (p less than 0.05) with risk of surgically treated BPH: age, low body mass index, nonsmoking (vs. current smoking), urine pH greater than 5, history of kidney x-ray and of tuberculosis, and each of five urologic symptoms (dysuria, loss of bladder control, trouble starting urination, nocturia, slow urine stream). The risk of BPH associated with obstructive urologic symptoms decreased markedly with age. Some of these findings are consistent with those from other studies (age, nonsmoking), while others (high urine pH, history of tuberculosis) are new and should be examined in other study populations.

Adult↗

PubMed1989

Risk for colorectal adenocarcinoma in pernicious anemia. A population-based cohort study.

STUDY OBJECTIVE: To determine the long-term risk for colorectal cancer among patients with pernicious anemia. DESIGN: Historical cohort study. SETTING: Population-based inception cohort of Rochester, Minnesota, residents. PATIENTS AND METHODS: We identified 150 Rochester residents who had the onset of pernicious anemia during the 30-year period from 1950 through 1979, and we followed this cohort for 1664 person-years of observation. The observed risk for subsequent colorectal cancer in the cohort was compared with that expected based on incidence rates of colon and rectal cancer for the local population. MEASUREMENTS AND MAIN RESULTS: There were 14 cases of colorectal cancer among the 150 patients with pernicious anemia (where 10.5 cases were expected), and 9 of these cases were found after the diagnosis of pernicious anemia was established (where 5.1 cases were expected). The relative risk for colon cancer at any time after the diagnosis of pernicious anemia was 1.8 (CI, 0.8 to 3.3). The relative risk was greatest (4.1; CI, 1.7 to 8.7) in the 5-year period immediately after the diagnosis of pernicious anemia; during this period, 7 cases of colon cancers were observed but only 1.7 were expected (P less than 0.0001). CONCLUSION: Although the overall risk does not achieve statistical significance, patients with pernicious anemia may have an increased risk for colorectal adenocarcinoma in the 5 years after diagnosis.

Adenocarcinoma↗

PubMed1988

Fatal upper gastrointestinal hemorrhage or perforation among users and nonusers of nonsteroidal anti-inflammatory drugs in Saskatchewan, Canada 1983.

We report a cohort study of fatal upper GI hemorrhage and/or perforation in relation to use of nonsteroidal anti-inflammatory drugs (NSAIDs) among the one million residents of Saskatchewan Canada in 1983. All hospitalized cases of GI hemorrhage and/or perforation with a fatal outcome were identified using the records linkage system of the Saskatchewan Department of Health. Discharge summaries and autopsy records were reviewed to select the cases of upper GI hemorrhage or upper GI perforation and to exclude cases in which known risk factors were present. The 134,060 residents who filled one or more prescriptions for an NSAID in 1983 were identified and individually linked to their hospital records by patient identification number. The age- and gender-specific incidence of fatal upper GI hemorrhage and/or perforation in the absence of risk factors in users was compared to that in nonusers, controlling for recent history of upper GI disease. Fatal upper GI hemorrhage or perforation in temporal association with NSAIDs is extremely rare in persons younger than 75 years of age. No temporally-related cases occurred in male NSAID users age 75 and older, but NSAID usage in this group was limited. Among women age 75 and older, the rate in users was higher than in nonusers, with the highest rate being in female NSAID users age 75 and older with a recent history of upper GI disease. Total mortality among women age 75 and older was slightly lower among users than among nonusers. Physicians who prescribe NSAIDs to patients age 75 and older should be aware of the potential risks, particularly in those with predisposing factors such as a history of upper GI disease.

Adult↗

PubMed1987

Epidemiologic programs for computers and calculators. Exact binomial confidence intervals for the relative risk in follow-up studies with sparsely stratified incidence density data.

The authors present a computer program for hypothesis testing and calculation of exact binomial confidence intervals for the adjusted relative risk in follow-up studies involving multiple strata with incidence density (person-time) denominators and small or zero person-count numerators. The program is an extension to multiple tables of a single-table method by Rothman and Boice (NIH publication no. 79-1649, Washington, DC: US GPO, 1979) and represents a counterpart for person-time denominators to the program of Thomas (Comput Biomed Res 1975;8:423-46) for exact analysis of multiple tables with person-count denominators. Comparisons with asymptotic analyses of real and simulated data are given. Copies of the program are available from the authors on request.

Adolescent↗

PubMedDate not supplied

Factors predictive of seizures among intensive care unit patients with gram-negative infections.

From the medical records of 238 intensive care unit (ICU) patients who had infections with gram-negative pathogens commonly associated with serious illness, we developed a predictive score of clinical risk factors for seizures. To evaluate the predictive ability of this score, we applied it to a separate population of 645 seriously ill hospitalized patients with similar gram-negative infections who were in antibiotic clinical trials. The patients at highest risk were classified into one of the following three categories: (a) patients with major central nervous system (CNS) insults (CNS surgery, hemorrhage, infection, or other lesion within 1 month before hospital admission or any history of CNS neoplasia), (b) patients with a predisposing factor (renal impairment or a history of seizures) plus a precipitating factor (anoxic encephalopathy/coma or an acute hypotensive episode), and (c) patients with both renal impairment and a history of seizures. Receiver operating characteristic (ROC) curves were calculated in each of the two populations. The area under the ROC curve (AUC) represents the probability that the score would rank a randomly chosen patient who subsequently had a seizure as having had a greater prior level of seizure risk than a randomly chosen patient who did not experience a seizure. The AUC was 0.87 (SE = 0.05) for the original population used to develop the score and 0.81 (SE = 0.04) for the population used for the validation study. The clinical risk score, based on readily available information, provides a useful means to identify among seriously ill infectious disease service patients, those who are at highest risk for seizures. It also serves as a baseline for evaluating the non-drug-related risk factors for seizures in patients treated with antibiotics.

Adult↗