Association of COVID-19 With Achieving Time-to-Surgery Benchmarks in Patients With Musculoskeletal Trauma

Question

Were resource constraints due to the COVID-19 pandemic associated with a delay in urgent fracture surgery beyond national time-to-surgery benchmarks?

Findings

In this cohort pre-post study that included 3589 patients, there was no association between time to surgery and COVID-19 in either open fracture or closed femur/hip fracture cohorts.

Meaning

Despite concerns that the unprecedented challenges associated with the COVID-19 pandemic would delay acute management of urgent surgery, many hospital systems within the US were able to implement strategies in keeping with time-to-surgery standards for orthopedic trauma.

Importance

In response to the COVID-19 pandemic, many hospital systems were forced to reduce operating room capacity and reallocate resources. The outcomes of these policies on the care of injured patients and the maintenance of emergency services have not been adequately reported.

Objective

To evaluate whether the COVID-19 pandemic was associated with delays in urgent fracture surgery beyond national time-to-surgery benchmarks.

Design, Setting, and Participants

This retrospective cohort study used data collected in the Program of Randomized Trials to Evaluate Preoperative Antiseptic Skin Solutions in Orthopaedic Trauma among at 20 sites throughout the US and Canada and included patients who sustained open fractures or closed femur or hip fractures.

Exposure

COVID-19–era operating room restrictions were compared with pre–COVID-19 data.

Main Outcomes and Measures

Surgery within 24 hours after injury.

Results

A total of 3589 patients (mean [SD] age, 55 [25.4] years; 1913 [53.3%] male) were included in this study, 2175 pre–COVID-19 and 1414 during COVID-19. A total of 54 patients (3.1%) in the open fracture cohort and 407 patients (21.8%) in the closed hip/femur fracture cohort did not meet 24-hour time-to-surgery benchmarks. We were unable to detect any association between time to operating room and COVID-19 era in either open fracture (odds ratio [OR], 1.40; 95% CI, 0.77-2.55; P = .28) or closed femur/hip fracture (OR, 1.01; 95% CI, 0.74-1.37; P = .97) cohorts. In the closed femur/hip fracture cohort, there was no association between time to operating room and regional COVID-19 prevalence (OR, 1.07; 95% CI, 0.70-1.64; P = .76).

Conclusions and Relevance

In this cohort study, there was no association between meeting time-to-surgery benchmarks in either open fracture or closed femur/hip fracture during the COVID-19 pandemic compared with before the pandemic. This is counter to concerns that the unprecedented challenges associated with managing the COVID-19 pandemic would be associated with clinically significant delays in acute management of urgent surgical cases and suggests that many hospital systems within the US were able to effectively implement policies consistent with time-to-surgery standards for orthopedic trauma in the context of COVID-19–related resource constraints.

Predictors of bacterial pneumonia in Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT)

BACKGROUND AND OBJECTIVES

Bacterial pneumonia still contributes to morbidity/mortality in HIV infection despite effective combination antiretroviral therapy (cART). Evaluation of Subcutaneous Interleukin-2 in a Randomized International Trial (ESPRIT), a trial of intermittent recombinant interleukin-2 (rIL-2) with cART vs. cART alone (control arm) in HIV-infected adults with CD4 counts ≥300cells/μL, offered the opportunity to explore associations between bacterial pneumonia and rIL-2, a cytokine that increases the risk of some bacterial infections.

METHODS

Baseline and time-updated factors associated with first-episode pneumonia on study were analysed using multivariate proportional hazards regression models. Information on smoking/pneumococcal vaccination history was not collected.

RESULTS

IL-2 cycling was most intense in years 1-2. Over ≈7 years, 93 IL-2 [rate 0.67/100 person-years (PY)] and 86 control (rate 0.63/100 PY) patients experienced a pneumonia event [hazard ratio (HR) 1.06; 95% confidence interval (CI) 0.79, 1.42; P=0.68]. Median CD4 counts prior to pneumonia were 570cells/μL (IL-2 arm) and 463cells/μL (control arm). Baseline risks for bacterial pneumonia included older age, injecting drug use, detectable HIV viral load (VL) and previous recurrent pneumonia; Asian ethnicity was associated with decreased risk. Higher proximal VL (HR for 1 log(10) higher VL 1.28; 95% CI 1.11, 1.47; P<0.001) was associated with increased risk; higher CD4 count prior to the event (HR per 100 cells/μL higher 0.94; 95% CI 0.89, 1.0; P=0.04) decreased risk. Compared with controls, the hazard for a pneumonia event was higher if rIL-2 was received <180 days previously (HR 1.66; 95% CI 1.07, 2.60; P=0.02) vs.≥180 days previously (HR 0.98; 95% CI 0.70, 1.37; P=0.9). Compared with the control group, pneumonia risk in the IL-2 arm decreased over time, with HRs of 1.41, 1.71, 1.16, 0.62 and 0.84 in years 1, 2, 3-4, 5-6 and 7, respectively.

CONCLUSIONS

Bacterial pneumonia rates in cART-treated adults with moderate immunodeficiency are high. The mechanism of the association between bacterial pneumonia and recent IL-2 receipt and/or detectable HIV viraemia warrants further exploration.

Interleukin-2 therapy in patients with HIV infection

BACKGROUND

Used in combination with antiretroviral therapy, subcutaneous recombinant interleukin-2 raises CD4+ cell counts more than does antiretroviral therapy alone. The clinical implication of these increases is not known.

METHODS

We conducted two trials: the Subcutaneous Recombinant, Human Interleukin-2 in HIV-Infected Patients with Low CD4+ Counts under Active Antiretroviral Therapy (SILCAAT) study and the Evaluation of Subcutaneous Proleukin in a Randomized International Trial (ESPRIT). In each, patients infected with the human immunodeficiency virus (HIV) who had CD4+ cell counts of either 50 to 299 per cubic millimeter (SILCAAT) or 300 or more per cubic millimeter (ESPRIT) were randomly assigned to receive interleukin-2 plus antiretroviral therapy or antiretroviral therapy alone. The interleukin-2 regimen consisted of cycles of 5 consecutive days each, administered at 8-week intervals. The SILCAAT study involved six cycles and a dose of 4.5 million IU of interleukin-2 twice daily; ESPRIT involved three cycles and a dose of 7.5 million IU twice daily. Additional cycles were recommended to maintain the CD4+ cell count above predefined target levels. The primary end point of both studies was opportunistic disease or death from any cause.

RESULTS

In the SILCAAT study, 1695 patients (849 receiving interleukin-2 plus antiretroviral therapy and 846 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 202 cells per cubic millimeter were enrolled; in ESPRIT, 4111 patients (2071 receiving interleukin-2 plus antiretroviral therapy and 2040 receiving antiretroviral therapy alone) who had a median CD4+ cell count of 457 cells per cubic millimeter were enrolled. Over a median follow-up period of 7 to 8 years, the CD4+ cell count was higher in the interleukin-2 group than in the group receiving antiretroviral therapy alone--by 53 and 159 cells per cubic millimeter, on average, in the SILCAAT study and ESPRIT, respectively. Hazard ratios for opportunistic disease or death from any cause with interleukin-2 plus antiretroviral therapy (vs. antiretroviral therapy alone) were 0.91 (95% confidence interval [CI], 0.70 to 1.18; P=0.47) in the SILCAAT study and 0.94 (95% CI, 0.75 to 1.16; P=0.55) in ESPRIT. The hazard ratios for death from any cause and for grade 4 clinical events were 1.06 (P=0.73) and 1.10 (P=0.35), respectively, in the SILCAAT study and 0.90 (P=0.42) and 1.23 (P=0.003), respectively, in ESPRIT.

CONCLUSIONS

Despite a substantial and sustained increase in the CD4+ cell count, as compared with antiretroviral therapy alone, interleukin-2 plus antiretroviral therapy yielded no clinical benefit in either study. (ClinicalTrials.gov numbers, NCT00004978 [ESPRIT] and NCT00013611 [SILCAAT study].)

Can emergency department physicians safely and effectively initiate thrombolysis for acute ischemic stroke?

OBJECTIVE

To review the clinical outcomes of stroke patients treated with IV tissue plasminogen activator (tPA; alteplase) in a community setting and to compare outcomes when treatment was initiated by a neurologist or an emergency department (ED) physician in telephone consultation with a neurologist and radiologist.

METHODS

Clinical information was prospectively collected for 43 stroke patients treated with IV tPA (alteplase) within a five-hospital network of affiliated community hospitals. Blinded 3-month outcomes were obtained with telephone interview or patient visit.

RESULTS

Excellent functional recovery measured by a Modified Rankin score of 0 to 1 (42%), symptomatic intracerebral hemorrhages (7%), and mortality (16.3%) were similar to those reported by National Institute of Neurological Disorders and Stroke (39%, 7.7%, 17.3%). After initial screening by an ED physician, 20 patients were directly examined by a stroke neurologist who then prescribed tPA. Twenty-three patients received tPA prescribed by an ED physician after telephone consultation with a neurologist and review of the head CT by a radiologist. Functional outcome, symptomatic intracerebral bleeding rate, and mortality rate were similar between these groups. Door-to-needle time was similar. Protocol deviations were much higher when ED physicians prescribed the tPA compared to when neurologists did (30% versus 5%). These protocol deviations were reduced with staff education.

CONCLUSIONS

The clinical results of the National Institute of Neurological Disorders and Stroke tPA Stroke Trial were replicated in this small series of patients treated in a community setting. Outcomes were similar whether the prescribing physician was a neurologist or an ED physician.

Low risk-factor profile and long-term cardiovascular and noncardiovascular mortality and life expectancy: findings for 5 large cohorts of young adult and middle-aged men and women

CONTEXT

Three major coronary risk factors-serum cholesterol level, blood pressure, and smoking-increase incidence of coronary heart disease (CHD) and related end points. In previous investigations, risks for low-risk reference groups were estimated statistically because samples contained too few such people to measure risk.

OBJECTIVE

To measure long-term mortality rates for individuals with favorable levels for all 3 major risk factors, compared with others.

DESIGN

Two prospective studies, involving 5 cohorts based on age and sex, that enrolled persons with a range of risk factors. Low risk was defined as serum cholesterol level less than 5.17 mmol/L (<200 mg/dL), blood pressure less than orequal to 120/80 mm Hg, and no current cigarette smoking. All persons with a history of diabetes, myocardial infarction (MI), or, in 3 of 5 cohorts, electrocardiogram (ECG) abnormalities, were excluded.

SETTING AND PARTICIPANTS

In 18 US cities, a total of 72144 men aged 35 through 39 years and 270671 men aged 40 through 57 years screened (1973-1975) for the Multiple Risk Factor Intervention Trial (MRFIT); in Chicago, a total of 10025 men aged 18 through 39 years, 7490 men aged 40 through 59 years, and 6229 women aged 40 through 59 years screened (1967-1973) for the Chicago Heart Association Detection Project in Industry (CHA) (N = 366559).

MAIN OUTCOME MEASURES

Cause-specific mortality during 16 (MRFIT) and 22 (CHA) years, relative risks (RRs) of death, and estimated greater life expectancy, comparing low-risk subcohorts vs others by age strata.

RESULTS

Low-risk persons comprised only 4.8% to 9.9% of the cohorts. All 5 low-risk groups experienced significantly and markedly lower CHD and cardiovascular disease death rates than those who had elevated cholesterol level, or blood pressure, or smoked. For example, age-adjusted RRs of CHD mortality ranged from 0.08 for CHA men aged 18 to 39 years to 0.23 for CHA men aged 40 through 59 years. The age-adjusted relative risks (RRs) for all cardiovascular disease mortality ranged from 0.15 for MRFIT men aged 35 through 39 years to 0.28 for CHA men aged 40 through 59 years. The age-adjusted RR for all-cause mortality rate ranged from 0.42 for CHA men aged 40 through 59 years to 0.60 for CHA women aged 40 through 59 years. Estimated greater life expectancy for low-risk groups ranged from 5.8 years for CHA women aged 40 through 59 years to 9.5 years for CHA men aged 18 through 39 years.

CONCLUSIONS

Based on these very large cohort studies, for individuals with favorable levels of cholesterol and blood pressure who do not smoke and do not have diabetes, MI, or ECG abnormalities, long-term mortality is much lower and longevity is much greater. A substantial increase in the proportion of the population at lifetime low risk could contribute decisively to ending the CHD epidemic.

Acupuncture and amitriptyline for pain due to HIV-related peripheral neuropathy: a randomized controlled trial. Terry Beirn Community Programs for Clinical Research on AIDS

CONTEXT

Peripheral neuropathy is common in persons infected with the human immunodeficiency virus (HIV) but few data on symptomatic treatment are available.

OBJECTIVE

To evaluate the efficacy of a standardized acupuncture regimen (SAR) and amitriptyline hydrochloride for the relief of pain due to HIV-related peripheral neuropathy in HIV-infected patients.

DESIGN

Randomized, placebo-controlled, multicenter clinical trial. Each site enrolled patients into 1 of the following 3 options: (1) a modified double-blind 2 x 2 factorial design of SAR, amitriptyline, or the combination compared with placebo, (2) a modified double-blind design of an SAR vs control points, or (3) a double-blind design of amitriptyline vs placebo.

SETTING

Terry Beirn Community Programs for Clinical Research on AIDS (HIV primary care providers) in 10 US cities.

PATIENTS

Patients with HIV-associated, symptomatic, lower-extremity peripheral neuropathy. Of 250 patients enrolled, 239 were in the acupuncture comparison (125 in the factorial option and 114 in the SAR option vs control points option), and 136 patients were in the amitriptyline comparison (125 in the factorial option and 11 in amitriptyline option vs placebo option).

INTERVENTIONS

Standardized acupuncture regimen vs control points, amitriptyline (75 mg/d) vs placebo, or both for 14 weeks.

MAIN OUTCOME MEASURE

Changes in mean pain scores at 6 and 14 weeks, using a pain scale ranging from 0.0 (no pain) to 1.75 (extremely intense), recorded daily.

RESULTS

Patients in all 4 groups showed reduction in mean pain scores at 6 and 14 weeks compared with baseline values. For both the acupuncture and amitriptyline comparisons, changes in pain score were not significantly different between the 2 groups. At 6 weeks, the estimated difference in pain reduction for patients in the SAR group compared with those in the control points group (a negative value indicates a greater reduction for the "active" treatment) was 0.01 (95% confidence interval [CI], -0.11 to 0.12; P=.88) and for patients in the amitriptyline group vs those in the placebo group was -0.07 (95% CI, -0.22 to 0.08; P=.38). At 14 weeks, the difference for those in the SAR group compared with those in the control points group was -0.08 (95% CI, -0.21 to 0.06; P=.26) and for amitriptyline compared with placebo was 0.00 (95% CI, -0.18 to 0.19; P=.99).

CONCLUSIONS

In this study, neither acupuncture nor amitriptyline was more effective than placebo in relieving pain caused by HIV-related peripheral neuropathy.

Evidence for a neurotensin receptor in rat serosal mast cells

OBJECTIVE AND DESIGN

The ability of neurotensin (NT) at nmolar levels to stimulate exocytosis of the mast cell suggested that it could play a role in neuro-immune-endocrine interactions. The inhibition by a specific receptor antagonist of NT's mast cell stimulation suggested the presence of a specific mast cell NT receptor. We have here employed several probes to determine if a specific neurotensin receptor was present on rat serosal mast cells.

MATERIAL

Serosal mast cells were isolated from the peritoneal and pleural cavities of male Sprague-Dawley rats.

METHODS

Immunocytochemistry with an antibody raised against the C-terminal peptide of the neurotensin receptor was utilized. The same antibody was employed in immunoblotting following SDS gel electrophoresis of mast cell extracts. An RNA probe for ribonuclease protection assays (RPA) was prepared using the rat brain neurotensin receptor cDNA and polymerase chain reaction was carried out using primers based on the rat brain neurotensin receptor sequence.

RESULTS

Mast cells showed specific staining with the anti-neurotensin receptor antibody and this same antibody revealed a protein on SDS gels migrating as a 70 kDa species. Ribonuclease protection assays revealed the predicted protected fragment at approximately 450 bp while PCR amplification gave a major product at 843 bp.

CONCLUSIONS

These results indicate that a specific neurotensin receptor is present on the rat mast cell.

The effects of diuresis on the pharmacokinetics of the loop diuretics furosemide and torsemide in patients with heart failure

PURPOSE

To evaluate the pharmacokinetics of furosemide and torsemide before and after diuresis in patients presenting with marked fluid overload.

SUBJECTS AND METHODS

We studied 44 patients with New York Heart Association class III or IV heart failure, ejection fraction < or =40%, and an estimated excess fluid body weight > or =6.8 kg. Oral furosemide or torsemide was administered before and after diuresis. Pharmacokinetic parameters were assessed before and after diuresis.

RESULTS

Following diuresis, maximum plasma concentration increased from 11.0+/-5.0 microg/mL to 13.9+/-6.8 with torsemide (P <0.05) and from 3.1< or =1.5 to 3.9+/-1.9 with furosemide (P=0.16). Maximum concentration increased by more than 30% in only one third of the patients. Total absorption (by area under the curve method) increased 6% among patients on torsemide (P=0.38) and 7% among patients on furosemide (P=0.63) and increased >30% in only 1 torsemide and 2 furosemide patients. The time to maximum concentration decreased from 1.40+/-.82 h to 0.81+/-0.36 with torsemide (P <0.01). There were no differences between furosemide and torsemide in the effects of edema on absorption.

CONCLUSION

Marked diuresis altered the pharmacokinetics of both furosemide and torsemide in only a small percentage of patients. The use of adequate doses of oral diuretics in edematous patients may be successful, thereby permitting home treatment with oral diuretics and avoiding the cost of hospitalizations or home intravenous administration services.

Mortality differences between black and white men in the USA: contribution of income and other risk factors among men screened for the MRFIT. MRFIT Research Group. Multiple Risk Factor Intervention Trial

BACKGROUND

Studies of underlying differences in adult mortality between black and white individuals in the USA have been constrained by limitations of data or small study size. We investigated the extent to which differences in socioeconomic position between black and white men contribute to differences in all-cause and cause-specific mortality.

METHODS

361,662 men were screened for the Multiple Risk Factor Intervention Trial between 1973 and 1975, in 22 sites. Median family income of households by zipcode (postal) area of residence was available for 20,224 black and 300,685 white men as well as data on age, cigarette smoking, blood pressure, serum cholesterol, previous heart attack, and treatment for diabetes. We classified deaths during 16 years of follow-up into specific causes and compared differences in death rates between black men and white men, before and after adjustment for differences in income and other risk factors.

FINDINGS

Age-adjusted relative risk of death (black vs white) was 1.47 (95% CI 1.42-1.53). Adjustment for diastolic blood pressure, serum cholesterol, cigarette smoking, medication for diabetes, and previous admission to hospital for heart attack decreased the relative risk to 1.40 (1.35-1.46). Adjustment for income but not the other risk factors decreased the risk to 1.19 (1.14-1.24) and adjustment for other risk factors did not alter this estimate. For cardiovascular death, relative risk on adjustment for income was decreased from 1.36 to 1.09; for cancer from 1.47 to 1.25; and for non-cardiovascular and non-cancer deaths from 1.71 to 1.26. For some specific causes of death, including prostate cancer, myeloma, and hypertensive heart disease, the higher death rates among black men did not seem to reflect differences in income. Rates of death for suicide and melanoma were lower among black than white men, as were those for coronary heart disease after adjustment for income.

INTERPRETATION

Socioeconomic position is the major contributor to differences in death rates between black and white men. Differentials in mortality from some specific causes do not simply reflect differences in income, however, and more detailed investigations are needed of how differences are influenced by environmental exposures, lifetime socioeconomic conditions, lifestyle, racism, and other sociocultural and biological factors.

Socioeconomic differentials in mortality risk among men screened for the Multiple Risk Factor Intervention Trial: I. White men

OBJECTIVES

This study examined socioeconomic differentials in risk of death from a number of specific causes in a large cohort of White men in the United States.

METHODS

For 300 685 White men screened for the Multiple Risk Factor Intervention Trial between 1973 and 1975, data were collected on median income of White households in the zip code of residence, age, cigarette smoking, blood pressure, serum cholesterol, previous myocardial infarction, and drug treatment for diabetes. The 31 737 deaths that occurred over the 16-year follow-up period were grouped into specific causes and related to median White family income.

RESULTS

There was an inverse association between age- adjusted all-cause mortality and median family income. There was no attenuation of this association over the follow-up period, and the association was similar for the 22 clinical centers carrying out the screening. The gradient was seen for many-but not all-of the specific causes of death. Other risk factors accounted for some of the association between income and coronary heart disease and smoking-related cancers.

CONCLUSIONS

Socioeconomic position, as measured by median family income of area of residence, is an important determinant of mortality risk in White men.

Socioeconomic differentials in mortality risk among men screened for the Multiple Risk Factor Intervention Trial: II. Black men

OBJECTIVES

This study examined socioeconomic differentials in risk of death from a number of causes in a large cohort of Black men in the United States.

METHODS

For 20 224 Black men screened for the Multiple Risk Factor Intervention Trial between 1973 and 1975, data were collected on median family income of Black households in zip code of residence, age, cigarette smoking, blood pressure, serum cholesterol, previous heart attack, and drug treatment for diabetes. The 2937 deaths that occurred over the 16-year follow-up period were grouped into specific causes and related to median Black family income.

RESULTS

There was an inverse association between age-adjusted all-cause mortality and median family income. There was no attenuation of this association over the follow-up period, and the association was similar for the 22 clinical centers carrying out the screening. The gradient was seen for most of the specific causes of death, although the strength of the association varied. Median income was markedly lower for the Black men screened than for the White men, but the relationship between income and all-cause mortality was similar.

CONCLUSIONS

Socioeconomic position is an important determinant of mortality risk for Black men. Even though Blacks lived in areas with substantially lower median family income than Whites, the association of income with mortality was similar for Blacks and Whites.

Lithium-induced alterations in parathyroid cell function: insight into the pathogenesis of lithium-associated hyperparathyroidism

BACKGROUND

Reduced parathyroid sensitivity to changes in calcium (Ca2+) has been observed in patients treated with lithium (Li+). In order to investigate this desensitization phenomenon, the effect of Li+ on cytosolic calcium (Cai2+) regulation was examined.

METHODS

Transmembrane signal transduction and Ca2+ sequestration were investigated in bovine parathyroid cells by measuring changes in [Cai2+] in response to 5 mmol/L magnesium (Mg2+), 0.5 to 2.5 mmol/L Ca2+, 25 mumol/L adenosine triphosphate (ATP), and 1 mumol/L ionomycin in cells pretreated with 1 to 10 mmol/L lithium chloride (LiCl) and control cells. Measurement of Cai2+ was made using fura-2.

RESULTS

Increases in [Cai2+] in response to Ca2+ and Mg2+ were blunted following overnight culture with as low as 1 mmol/L LiCl. In normocalcemic medium, 1 mmol/L Ca2+ produced an 81% increase in [Cai2+] in control cells compared with a 58% increase in cells pretreated with LiCl (P < 0.01), whereas in hypocalcemic medium, increases in [Cai2+] were similar in lithium-treated and control cells (78% versus 82%, P > 0.1). The ATP produced increases in [Cai2+] from 225 +/- 9 nmol/L to 366 +/- 10 nmol/L in control cells, compared with 221 +/- 7 nmol/L to 308 +/- 10 nmol/L in cells pretreated with 5 mmol/L LiCl (P < 0.01). Ionomycin-induced increases in [Cai2+] were unaffected by Li+.

CONCLUSIONS

We concluded that the in vitro desensitizing effects of Li+ occur at therapeutic concentrations, but only in the presence of Ca2+ in concentrations that induce transmembrane signaling; and that Li+ blunts increases in [Cai2+] related to cation and ATP-induced transmembrane signal transduction without affecting ionomycin-releasable Ca2+ stores.

Risk factors for postthyroidectomy hypocalcemia

BACKGROUND

Hypocalcemia is a common sequela of thyroidectomy; however, its causative factors have not been completely delineated.

METHODS

A prospective study of 60 patients who underwent unilateral (n = 15) or bilateral (n = 45) thyroidectomy between 1990 and 1993 was completed to determine the incidence and risk factors for hypocalcemia. Free thyroxine, thyrotropin, and alkaline phosphatase levels were obtained before operation in all patients, together with preoperative and postoperative ionized calcium, parathyroid hormone (PTH), calcitonin, and 1,25-dihydroxyvitamin D3 levels. All patients were examined for age, gender, extent of thyroidectomy, initial versus reoperative neck surgery, weight and pathologic characteristics of resected thyroid tissue, substernal thyroid extension, and parathyroid resection and autotransplantation.

RESULTS

Hypocalcemia, defined by an ionized calcium level less than 4.5 mg/dl, occurred in 28 patients (47%), including nine (15%) symptomatic patients who required vitamin D and/or calcium for 2 to 6 weeks. In no patient did permanent hypoparathyroidism develop. With a multivariate logistic regression analysis, factors that were predictive of postoperative hypocalcemia included an elevated free thyroxine level (p = 0.003), cancer (p = 0.010), and substernal extension (p = 0.046).

CONCLUSIONS

Postoperative decline in parathyroid hormone was not an independent risk factor for hypocalcemia, indicating that other factors besides parathyroid injury, ischemia, or removal are involved in the pathogenesis of postthyroidectomy hypocalcemia. An elevated free thyroxine level, substernal thyroid disease, and carcinoma are risk factors for postthyroidectomy hypocalcemia, and their presence should warrant routine postoperative calcium measurement. In the absence of these risk factors, routine postoperative measurement of serum calcium is unnecessary.

Use of polymerase chain reaction to detect swine influenza virus in nasal swab specimens

Rapid and accurate detection of a virus in a population is a critical factor in the eventual treatment and/or control of the virus. In this study, we examined use of the polymerase chain reaction (PCR) to detect swine influenza virus in nasal swab specimens from infected pigs. This approach was first standardized, using viral RNA purified by guanidinium/phenol-chloroform extraction and placed in the same transport medium as the swabs. By using highly conserved primers for the swine H1 hemagglutinin, we amplified a 591-base pair fragment that was analyzed by use of agarose gel electrophoresis, Southern blot, and DNA sequencing. To evaluate PCR as a potential diagnostic tool for detection of swine influenza virus infection, we obtained nasal swab specimens from experimentally infected pigs. Amplification by PCR and reamplification of extracted samples with internal primers yielded detectable bands for an amount of virus less than that required to infect embryonating chicken eggs. We also tested swab specimens from pigs involved in 3 separate, natural episodes of swine influenza. These swab specimens were extracted, amplified and reamplified, producing visible bands on the gel and in Southern blots. We performed Southern blot analyses on all PCR products, to confirm that they were from viral H1 RNA. We also cloned and sequenced a 591-base pair product from 1 specimen and found that it was 100% identical to the hemagglutinin gene sequence of A/Sw/Ind/1726/88. Results indicate that PCR can be used to detect swine influenza virus, even in nasal swab specimens, the specimen typically collected for diagnosis of virus infection.

Diabetes, other risk factors, and 12-yr cardiovascular mortality for men screened in the Multiple Risk Factor Intervention Trial

OBJECTIVE

To assess predictors of CVD mortality among men with and without diabetes and to assess the independent effect of diabetes on the risk of CVD death.

RESEARCH DESIGN AND METHODS

Participants in this cohort study were screened from 1973 to 1975; vital status has been ascertained over an average of 12 yr of follow-up (range 11-13 yr). Participants were 347,978 men aged 35-57 yr, screened in 20 centers for MRFIT. The outcome measure was CVD mortality.

RESULTS

Among 5163 men who reported taking medication for diabetes, 1092 deaths (603 CVD deaths) occurred in an average of 12 yr of follow-up. Among 342,815 men not taking medication for diabetes, 20,867 deaths were identified, 8965 ascribed to CVD. Absolute risk of CVD death was much higher for diabetic than nondiabetic men of every age stratum, ethnic background, and risk factor level--overall three times higher, with adjustment for age, race, income, serum cholesterol level, sBP, and reported number of cigarettes/day (P < 0.0001). For men both with and without diabetes, serum cholesterol level, sBP, and cigarette smoking were significant predictors of CVD mortality. For diabetic men with higher values for each risk factor and their combinations, absolute risk of CVD death increased more steeply than for nondiabetic men, so that absolute excess risk for diabetic men was progressively greater than for nondiabetic men with higher risk factor levels.

CONCLUSIONS

These findings emphasize the importance of rigorous sustained intervention in people with diabetes to control blood pressure, lower serum cholesterol, and abolish cigarette smoking, and the importance of considering nutritional-hygienic approaches on a mass scale to prevent diabetes.

Serum cholesterol level and mortality findings for men screened in the Multiple Risk Factor Intervention Trial. Multiple Risk Factor Intervention Trial Research Group

BACKGROUND

With increased efforts to lower serum cholesterol levels, it is important to quantify associations between serum cholesterol level and causes of death other than coronary heart disease, for which an etiologic relationship has been established.

METHODS

For an average of 12 years, 350,977 men aged 35 to 57 years who had been screened for the Multiple Risk Factor Intervention Trial were followed up following a single standardized measurement of serum cholesterol level and other coronary heart disease risk factors; 21,499 deaths were identified.

RESULTS

A strong, positive, graded relationship was evident between serum cholesterol level measured at initial screening and death from coronary heart disease. This relationship persisted over the 12-year follow-up period. No association was noted between serum cholesterol level and stroke. The absence of an association overall was due to different relationships of serum cholesterol level with intracranial hemorrhage and nonhemorrhagic stroke. For the latter, a positive, graded association with serum cholesterol level was evident. For intracranial hemorrhage, cholesterol levels less than 4.14 mmol/L (less than 160 mg/dL) were associated with a twofold increase in risk. A serum cholesterol level less than 4.14 mmol/L (less than 160 mg/dL) was also associated with a significantly increased risk of death from cancer of the liver and pancreas; digestive diseases, particularly hepatic cirrhosis; suicide; and alcohol dependence syndrome. In addition, significant inverse graded associations were found between serum cholesterol level and cancers of the lung, lymphatic, and hematopoietic systems, and chronic obstructive pulmonary disease. No significant associations were found of serum cholesterol level with death from colon cancer, with accidental deaths, or with homicides. Overall, the inverse association between serum cholesterol level and most cancers weakened with increasing follow-up but did not disappear. The association between cholesterol level and death due to cancer of the lung and liver, chronic obstructive pulmonary disease, cirrhosis, and suicide weakened little over follow-up.

CONCLUSIONS

The association of serum cholesterol with specific causes of death varies in direction, strength, gradation, and persistence. Further research on the determinants of low serum cholesterol level in populations and long-term follow-up of participants in clinical trials are necessary to assess whether inverse associations with noncardiovascular disease causes of death are consequences of noncardiovascular disease, whether serum cholesterol level and noncardiovascular disease are both consequences of other factors, or whether these associations are causal.

Serum cholesterol concentration and primary malignant brain tumors: a prospective study

Case-control studies and a prospective study have suggested a positive relation between serum cholesterol and brain tumors. To examine this association further, mortality from malignant brain tumors among men who participated in the Multiple Risk Factor Intervention Trial (a prospective study, 1973-1986) who indicated they were not black were examined. No relation was seen between age-standardized mortality rates and baseline serum cholesterol. Excluding deaths occurring during the first 5 years or adjusting for median census tract income did not alter this finding. This suggests that no generalizable relation between serum cholesterol and primary malignant brain tumors exists. An environmental factor associated with serum cholesterol in some, but not all populations, may explain the apparently contradictory results.

Serum cholesterol, blood pressure, cigarette smoking, and death from coronary heart disease. Overall findings and differences by age for 316,099 white men. Multiple Risk Factor Intervention Trial Research Group

To assess the combined influence of blood pressure (BP), serum cholesterol level, and cigarette smoking on death from coronary heart disease (CHD) and to describe how these associations vary with age, data on those factors and on mortality for 316,099 men screened for the Multiple Risk Factor Intervention Trial (MRFIT) were examined. Vital status of participants has been determined after an average follow-up of 12 years; 6327 deaths from CHD have been identified. Strong graded relationships between serum cholesterol levels above 4.65 mmol/L (180 mg/dL), systolic BP above 110 mm Hg, and diastolic BP above 70 mm Hg and mortality due to CHD were evident. Smokers with serum cholesterol and systolic BP levels in the highest quintiles had CHD death rates that were approximately 20 times greater than nonsmoking men with systolic BP and cholesterol levels in the lowest quintile. Systolic and diastolic BP, serum cholesterol level, and cigarettes per day were significant predictors of death due to CHD in all age groups. Systolic BP was a stronger predictor than diastolic BP. These results, together with the findings of clinical trials, offer strong support for intensified preventive efforts in all age groups.

Predictors of prism response during prism adaptation. Prism Adaptation Study Research Group

Results of the Prism Adaptation Study (PAS) indicate that prism adaptation improves the success rate of strabismus surgery for patients with acquired esotropia. Patients who show a fusion response to the prisms benefit most from this preoperative treatment. This study analyzes the characteristics of those patients who were and were not prism responders in the PAS. Significant factors predicting a prism response included: patients who were older at the time of onset of their esodeviation (P = .007), duration of deviation less than 1 year (P = .04), alternating fixation (P = .003), fusion on the Worth four-dot test at near with prism neutralization (P = .008), and equal vision (P = .009). Demographic characteristics were similar for both responders and nonresponders except that non-Hispanic patients were significantly more likely to respond to prisms than Hispanic patients (P less than .002). No test or characteristic was found which could reliably predict the prism response. Therefore, all patients with acquired esodeviations should be considered candidates for prism adaptation prior to strabismus surgery.

An examination of the efficiency of some quality assurance methods commonly employed in clinical trials

The cost and efficiency of training clinical centre staff and of duplicate data entry in clinical trials is reviewed. Training is an essential component of quality assurance programmes and it is usually carried out at regular intervals in long-term clinical trials. Initial training of staff and regular retraining is important to assure standardization and it can lead to reduced trial costs. Interim training for new staff and for remedial purposes is less efficient than regularly scheduled training sessions. Regional centres for training and the use of computer aided instruction are two ways such interim training can be made more efficient and standardized. Duplicate data entry or verification can result in a substantial reduction in data entry errors depending on the nature of the data being keyed. Selective verification should especially be considered for important fields for which consistency checks cannot be performed, that are alphabetic or that are several characters in length. Quality assurance procedures should be implemented to monitor data entry accuracy in clinical trials.

Serum cholesterol levels and six-year mortality from stroke in 350,977 men screened for the multiple risk factor intervention trial

We examined the relation between the serum total cholesterol level and the risk of death from stroke during six years of follow-up in 350,977 men, 35 to 57 years of age, who had no history of heart attack and were not currently being treated for diabetes mellitus. The diagnosis of stroke and the type of stroke were obtained from death certificates. Using proportional-hazards regression to control for age, cigarette smoking, diastolic blood pressure, and race or ethnic group, we found that the six-year risk of death from intracranial hemorrhage (International Classification of Diseases, ninth edition [ICD-9], categories 431 and 432) was three times higher in men with serum cholesterol levels under 4.14 mmol per liter (160 mg per deciliter) than in those with higher cholesterol levels (P = 0.05 by omnibus test across five cholesterol levels). On the other hand, a positive association was observed between the serum cholesterol level and death from nonhemorrhagic stroke (P = 0.007). The inverse association of the serum cholesterol level with the risk of death from intracranial hemorrhage was confined to men with diastolic blood pressure greater than or equal to 90 mm Hg, in whom death from intracranial hemorrhage is relatively common. We conclude that there is an inverse relation between the serum cholesterol level and the risk of death from hemorrhagic stroke in middle-aged American men, but that its public health impact is overwhelmed by the positive association of higher serum cholesterol levels with death from nonhemorrhagic stroke and total cardiovascular disease (ICD-9 categories 390 through 459).

Interleukin-2 self-association

The self-association of human recombinant interleukin-2 (IL-2) from E. coli was explored. Self-association, with an apparent Kd of 0.6 micromolar, has pronounced effects on (1) the surface exposure of Trp-121, deduced from quenching studies employing potassium iodide and acrylamide, (2) the apparent quantum yield of Trp-121, the fluorescence of Trp-121 in IL-2 aggregates is 4-fold lower than in IL-2 "monomers", and (3) IL-2-mediated phospholipid vesicle fusion/aggregation.

Comparability of ophthalmic diagnoses by clinical and Reading Center examiners in the Visual Acuity Impairment Survey Pilot Study

Technologic advances in ophthalmic equipment offer the possibility of replacing direct clinical examinations with Reading Center evaluations of data recorded in epidemiologic studies. Clinical and Reading Center examiners made independent ophthalmic diagnoses of 133 right and 132 left eyes of 138 adults in the Visual Acuity Impairment Survey Pilot Study, carried out in three US cities, Boston, Detroit, and Minneapolis, in August 1981-December 1982. The Reading Center diagnosed eye conditions using only photographic and visual field data collected at the time of the clinical examination. In the comparisons of clinical and Reading Center evaluations reported here, only eyes judged by the examiners to have pathology severe enough to reduce visual acuity to 6/9 or worse were classified as having pathology. (No visual acuity criterion was required for the diagnosis of glaucoma or diabetic retinopathy.) There was agreement in diagnostic assessments between clinical and Reading Center examiners in about 80% of eyes. The kappa statistic, which adjusts for chance agreement, was in the fair to good range: 0.60 for 133 right eyes and 0.62 for 132 left eyes. When the Reading Center examiners were provided with additional information on medical history, refractive error and best corrected visual acuity, the agreement between clinical and Reading Center assessments among the subset of eyes with 6/9 or worse vision again was in the fair to good range, with kappas of 0.61 for 45 right eyes and 0.68 for 48 left eyes. Inter-observer agreement between Reading Center examiners in diagnosing pathology was in the good to excellent range. Use of Reading Centers in future epidemiologic studies should be considered, but elimination of the clinical examinations is not recommended until modifications in the protocol described here have been made and shown to improve levels of agreement between clinical and Reading Center examiners.

Is relationship between serum cholesterol and risk of premature death from coronary heart disease continuous and graded? Findings in 356,222 primary screenees of the Multiple Risk Factor Intervention Trial (MRFIT)

The 356,222 men aged 35 to 57 years, who were free of a history of hospitalization for myocardial infarction, screened by the Multiple Risk Factor Intervention Trial (MRFIT) in its recruitment effort, constitute the largest cohort with standardized serum cholesterol measurements and long-term mortality follow-up. For each five-year age group, the relationship between serum cholesterol and coronary heart disease (CHD) death rate was continuous, graded, and strong. For the entire group aged 35 to 57 years at entry, the age-adjusted risks of CHD death in cholesterol quintiles 2 through 5 (182 to 202, 203 to 220, 221 to 244, and greater than or equal to 245 mg/dL [4.71 to 5.22, 5.25 to 5.69, 5.72 to 6.31, and greater than or equal to 6.34 mmol/L]) relative to the lowest quintile were 1.29, 1.73, 2.21, and 3.42. Of all CHD deaths, 46% were estimated to be excess deaths attributable to serum cholesterol levels 180 mg/dL or greater (greater than or equal to 4.65 mmol/L), with almost half the excess deaths in serum cholesterol quintiles 2 through 4. The pattern of a continuous, graded, strong relationship between serum cholesterol and six-year age-adjusted CHD death rate prevailed for nonhypertensive nonsmokers, nonhypertensive smokers, hypertensive nonsmokers, and hypertensive smokers. These data of high precision show that the relationship between serum cholesterol and CHD is not a threshold one, with increased risk confined to the two highest quintiles, but rather is a continuously graded one that powerfully affects risk for the great majority of middle-aged American men.

Serum cholesterol, blood pressure, and mortality: implications from a cohort of 361,662 men

The risks associated with various levels of serum cholesterol were determined by analysis of 6-year mortality in 361,662 men aged 35-57. Above the 20th percentile for serum cholesterol (greater than 181 mg/dl, greater than 4.68 mmol/l), coronary heart disease (CHD) mortality increased progressively; the relative risk was large (3.8) in the men with cholesterol levels above the 85th percentile (greater than 253 mg/dl, greater than 6.54 mmol/l). When men below the 20th cholesterol percentile were used as the baseline risk group, half of all CHD deaths were associated with raised serum cholesterol concentrations; half of these excess deaths were in men with cholesterol levels above the 85th percentile. For both CHD and total mortality, serum cholesterol was similar to diastolic blood pressure in the shape of the risk curve and in the size of the high-risk group. This new evidence supports the policy of a moderate fat intake for the general population and intensive treatment for those at high risk. There is a striking analogy between serum cholesterol and blood pressure in the epidemiological basis for identifying a large segment of the population (10-15%) for intensive treatment.

Overall and coronary heart disease mortality rates in relation to major risk factors in 325,348 men screened for the MRFIT. Multiple Risk Factor Intervention Trial

The influence of risk factors on CHD and all-cause mortality rates in 35- to 57-year-old men is examined by means of data on 325,348 white men who were screened for the MRFIT. This large data set permits an unusually detailed analysis of factors associated with the 6968 deaths, including 2426 ascribed to CHD, that were detected in the Social Security Administration data set during 6 years of follow-up. Simple cross classification of the data confirms the independent effect of serum cholesterol concentration, diastolic blood pressure, and cigarette smoking as risk factors for CHD and all-cause mortality rates. A distinct escalation of risk is noted for combinations of these risk factors. The strength of the association of each of the risk factors with CHD and all-cause mortality rates diminished with increasing age, although the number of excess deaths attributable to the risk factors increased because of the higher death rates in older men. Comparison of these findings with those observed in the five populations studied in the Pooling Project revealed an overall similarity in the risk relationships. It is estimated that elimination of these risk factors has the potential for reducing the CHD mortality rate by two thirds in 35- to 45-year old men, and by one half in 46- to 57-year-old men.

Prevalence and prognostic significance of hypercholesterolemia in men with hypertension. Prospective data on the primary screenees of the Multiple Risk Factor Intervention Trial

To assess the impact of serum cholesterol level on the risk of fatal coronary heart disease for men with high blood pressure, the six-year follow-up data from 361,662 men (aged 35 to 57 years) screened in 18 cities in the recruitment effort for the Multiple Risk Factor Intervention Trial were evaluated. Of these men, 356,222 reported no history of hospitalization for myocardial infarction; 100,032 of these 356,222 had a baseline mean diastolic blood pressure equal to or greater than 90 mm Hg. For those men with high blood pressure, the overall age-adjusted six-year rate of coronary heart disease death was 79 percent higher than for those with diastolic blood pressure less than 90 mm Hg. Compared with men with diastolic blood pressure less than 90 mm Hg and serum cholesterol below 182 mg/dl, men with diastolic blood pressure equal to or greater than 90 mm Hg had the following relative risks, based on the serum cholesterol level: for those with a serum cholesterol level less than 182 mg/dl, risk was 1.64; for those with a level of 182 to 202 mg/dl, risk was 2.14; for those with a level of 203 to 220 mg/dl, risk was 3.14; for those with a level of 221 to 244 mg/dl, risk was 3.29; and for those with a level equal to or greater than 245 mg/dl, risk was 5.14. Thus, for men with high blood pressure, serum cholesterol related to coronary heart disease risk in a strong, graded way, over the entire distribution of serum cholesterol, from levels of 182 mg/dl and higher. This was the case for hypertensive male smokers and nonsmokers, with cigarette use associated with a further marked increase in risk--at least a doubling of the mortality rate--at any level of serum cholesterol. These data underscore the necessity for a strategy of comprehensive care for persons with high blood pressure, including approaches to both nutritional and hygienic counseling and drug treatment, aimed at controlling all of the established major risk factors influencing prognosis.

Lessons from the Visual Acuity Impairment Survey pilot study

The Visual Acuity Impairment Survey (VAIS) pilot study was carried out in three large metropolitan areas of the United States to determine whether it would be feasible to conduct a large two-stage survey of the prevalence of visual acuity impairment and its causes. The study was conducted in conjunction with the Health Interview Survey (HIS), performed by the National Center for Health Statistics and the Census Bureau. In the first stage, a simple vision screening test was administered to 1,868 adults in their homes by specially trained Census Bureau interviewers. All those who failed the test, and a sample of those who passed it, were invited to a local clinic for a check on the accuracy of the screen and a detailed eye examination to establish the cause of the impairment. About 89 per cent of the HIS interviewees took the vision screening test in the home and agreed to have the results released, making it possible for the clinic to invite them for an examination. The principal obstacle to the success of the feasibility study was a low rate (less than 50 per cent) of participation in the clinic examination by the target population. Such low participation would leave the survey open to a serious question about its representativeness. The methods and findings of the pilot study are presented because the lessons may be of value to those attempting similar studies in the future. Suggestions are made for methodological modifications that may enhance the chances for success.

Total and cardiovascular mortality in relation to cigarette smoking, serum cholesterol concentration, and diastolic blood pressure among black and white males followed up for five years

The Multiple Risk Factor Intervention Trial screening program provided an opportunity (1) to study the association of diastolic blood pressure level, serum cholesterol concentration, and cigarettes per day with all-cause and cause-specific mortality after 5 years among 23,490 black males and (2) to compare these associations with those observed among 325,384 white males. The relationship of serum cholesterol concentration and reported cigarettes per day to all-cause, coronary heart disease (CHD), and cerebrovascular disease mortality was similar for black and white males. Diastolic blood pressure was more positively associated with cerebrovascular disease death among black males than white males (p = 0.047) according to logistic regression analysis. The lower CHD mortality among black males compared to white males was most apparent among hypertensive males (diastolic blood pressure greater than or equal to 90 mm Hg). The relative risk (black vs white) of CHD death adjusted for age, serum cholesterol concentration, and cigarettes per day was 0.69 for hypertensive males compared to 1.15 for nonhypertensive males (p = 0.012 for difference in relative risk estimates). These findings suggest that the causes of CHD and cerebrovascular disease may be different for black and white males, particularly in regard to how these disease processes relate to blood pressure.