National trends in the mortality of children with sickle cell disease, 1968 through 1992

The clinical spectrum of HbSC sickle cell disease-not a benign condition

Sickle cell disease (SCD) includes a group of heterogenous disorders that result in significant morbidities. HbSS is the most common type of SCD and HbSC is the second most common type of SCD. The prevalence of HbSC disease in the United States and United Kingdom is ~1 in 7174 births and 1 in 6174 births respectively. Despite its frequency, however, HbSC disease has been insufficiently studied and was historically categorized as a more 'mild' form of SCD. We conducted this study of HbSC disease as part of the NHLBI funded Sickle Cell Disease Implementation Consortium (SCDIC). The SCDIC registry included 2282 individuals with SCD, ages 15-45 years of whom 502 (22%) had HbSC disease. Compared with people with sickle cell anaemia (SCA), the study found that people with HbSC disease had a higher frequency of splenomegaly (n (%) = 169 (33.7) vs. 392 (22.1)) and retinopathy (n (%) = 116 (23.1) vs. 189 (10.6)). A Many people with HbSC also had avascular necrosis (n (%) = 112 (22.3)), pulmonary embolism (n (%) = 43 (8.6)) and acute chest syndrome (n (%) = 228 (45.4)) demonstrating significant disease severity. HbSC disease is more clinically severe than was previously recognized and deserves additional evaluation and targeted treatments.

Satisfaction and access to care for adults and adolescents with sickle cell disease: ASCQ-Me quality of care and the SHIP-HU study

A lack of adult sickle cell providers has long been blamed for poor satisfaction and access to specialty care for adults with sickle cell disease (SCD). We were interested in comparing how adolescent and adult patients already in established SCD centers perceived access and quality of care. Hydroxyurea-eligible patients aged 15 years and older were enrolled in the Start Healing in Patients with Hydroxyurea trial, which required them to be affiliated with a SCD specialist. Patients were seen in one of three adult-oriented specialty clinic sites or one of three pediatric-oriented sites. At baseline, patients completed the Adult Sickle Cell Quality of Life Measurement Information System measure as part of a survey battery. Patients treated at adult clinic sites reported being less able to get timely ambulatory appointments (p = .004). They reported emergency department (ED) wait times of >1 h far more often (47.7 vs. 19.3%, p = .0048). They reported less overall satisfaction with care (7.47 vs. 8.77, p < .0001), and less satisfaction with care in the ED (2.88 vs. 3.4, p = .0068. Ambulatory satisfaction was no different between pediatric site versus adult site patients. Poorer systems of care appeared to underlie reported differences, rather than differences in biopsychosocial determinants. Even among specialty-care-affiliated SCD patients, those seen in adult clinics reported worse access to care and lower satisfaction with care than patients seen in pediatric clinics. In addition to increasing the number of adult SCD providers and better preparing pediatric SCD patients to transfer to adult programs, SCD clinical caregivers must also improve aspects of adult care quality to meet reasonable patient expectations of timeliness and interpersonal aspects of care quality.

A randomised controlled provider-blinded trial of community health workers in sickle cell anaemia: effects on haematologic variables and hydroxyurea adherence

Hydroxyurea (hydroxycarbamide) (HU) for sickle cell anaemia (SCA) is underutilised. Case management is an evidence-based health management strategy and in this regard patient navigators (PNs) may provide case management for SCA. We hypothesised that HU-eligible patients exposed to PNs would have improved indicators of starting HU and HU adherence. We randomised 224 HU-eligible SCA adults into the Start Healing in Patients with Hydroxyurea (SHIP-HU) Trial. All patients received care from trained physicians using standardised HU prescribing protocols. Patients in the Experimental arm received case management and education from PNs through multiple contacts. All other patients were regarded as the Control arm and received specialty care alone. Study physicians were blinded to the study arms and did not interact with PNs. At baseline, 6 and 12 months we assessed and compared laboratory parameters and HU adherence indicators. Experimental patients had higher 6-month mean fetal haemoglobin (HbF) levels than controls. But at 12 months, mean HbF was similar, as were white blood cell count, absolute neutrophil count, total haemoglobin, platelet count and mean corpuscular volume. At 12 months there were fewer experimental patients missing HU doses than controls (mean 1·8 vs. 4·5, P = 0·0098), and more recent HU prescriptions filled than for controls (mean 53·8 vs. 92 days, median 27·5 vs. 62 days, P = 0·0082). Mean HU doses were largely similar. We detected behavioural improvements in HU adherence but no haematological improvements by adding PNs to specialty care.

Trends in Sickle Cell Disease-Related Mortality in the United States, 1979 to 2017

STUDY OBJECTIVE

We provide an updated assessment of trends in sickle cell disease (SCD)-related mortality, a significant source of mortality in the United States among black persons, using 1979 to 2017 US mortality data.

METHODS

SCD-related deaths were identified with International Classification of Diseases codes. Because SCD-related death is rare in other races, the analysis focused on black decedents. Age-specific and average annual SCD-related death rates were calculated. Causes of death codes were categorized into 20 groups relevant to SCD outcomes. SCD-related deaths were compared with non-SCD-related deaths after matching on race, sex, age group, and year of death.

RESULTS

There were 25,665 SCD-related deaths reported among blacks in the United States from 1979 through 2017. During that period, the annual SCD-related death rate declined in children and increased in adults, and the median age at death increased from 28 to 43 years. Acute causes of death, such as infection and cerebrovascular complications, were more common in younger age groups. Chronic complications were more common in adults. SCD-related deaths were more likely to be related to acute cardiac, pulmonary, and cerebrovascular complications; acute infections; and chronic cardiac and pulmonary complications and renal disorders; and less likely to be related to drug overdose and chronic infections than non-SCD-related deaths.

CONCLUSION

These data indicate SCD-related deaths are now more likely to be related to chronic complications of the disease than to acute complications. More research regarding prevention and treatment of chronic complications of SCD is necessary because persons with SCD are living longer.

A Complicated Case of Vaccine Refusal

Parents in the United States have a legal right to refuse vaccination for their children. There are, however, special circumstances under which the state may compel vaccination against parental wishes. In this Ethics Rounds article, we present the case of a young boy with sickle cell disease who was partially vaccinated against encapsulated bacteria and the ethics of whether to compel complete vaccination before splenectomy.

Comorbidity, Pain, Utilization, and Psychosocial Outcomes in Older versus Younger Sickle Cell Adults: The PiSCES Project

Background. Patients with SCD now usually live well into adulthood. Whereas transitions into adulthood are now often studied, little is published about aging beyond the transition period. We therefore studied age-associated SCD differences in utilization, pain, and psychosocial variables. Methods. Subjects were 232 adults in the Pain in Sickle Cell Epidemiology Study (PiSCES). Data included demographics, comorbidity, and psychosocial measures. SCD-related pain and health care utilization were recorded in diaries. We compared 3 age groups: 16–25 (transition), 26–36 (younger adults), and 37–64 (older adults) years. Results. Compared to the 2 adult groups, the transition group reported fewer physical challenges via comorbidities, somatic complaints, and pain frequency, though pain intensity did not differ on crisis or noncrisis pain days. The transition group utilized opioids less often, made fewer ambulatory visits, and had better quality of life, but these differences disappeared after adjusting for pain and comorbidities. However, the transition group reported more use of behavioral coping strategies. Conclusion. We found fewer biological challenges, visits, and better quality of life, in transition-aged versus older adults with SCD, but more behavioral coping. Further study is required to determine whether age-appropriate health care, behavioral, or other interventions could improve age-specific life challenges of patients with SCD.

Community Health Workers as Support for Sickle Cell Care

Community health workers are increasingly recognized as useful for improving health care and health outcomes for a variety of chronic conditions. Community health workers can provide social support, navigation of health systems and resources, and lay counseling. Social and cultural alignment of community health workers with the population they serve is an important aspect of community health worker intervention. Although community health worker interventions have been shown to improve patient-centered outcomes in underserved communities, these interventions have not been evaluated with sickle cell disease. Evidence from other disease areas suggests that community health worker intervention also would be effective for these patients. Sickle cell disease is complex, with a range of barriers to multifaceted care needs at the individual, family/friend, clinical organization, and community levels. Care delivery is complicated by disparities in health care: access, delivery, services, and cultural mismatches between providers and families. Current practices inadequately address or provide incomplete control of symptoms, especially pain, resulting in decreased quality of life and high medical expense. The authors propose that care and care outcomes for people with sickle cell disease could be improved through community health worker case management, social support, and health system navigation. This paper outlines implementation strategies in current use to test community health workers for sickle cell disease management in a variety of settings. National medical and advocacy efforts to develop the community health workforce for sickle cell disease management may enhance the progress and development of "best practices" for this area of community-based care.

Mortality of New York children with sickle cell disease identified through newborn screening

PURPOSE

Long-term follow-up of newborn screening for conditions such as sickle cell disease can be conducted using linkages to population-based data. We sought to estimate childhood sickle cell disease mortality and risk factors among a statewide birth cohort with sickle cell disease identified through newborn screening.

METHODS

Children with sickle cell disease identified by newborn screening and born to New York residents in 2000-2008 were matched to birth and death certificates. Mortality rates were calculated (using numbers of deaths and observed person-years at risk) and compared with mortality rates for all New York children by maternal race/ethnicity. Stratified analyses were conducted to examine associations between selected factors and mortality.

RESULTS

Among 1,911 infants with sickle cell disease matched to birth certificates, 21 deaths were identified. All-cause mortality following diagnosis was 3.8 per 1,000 person-years in the first 2 years of life and 1.0 per 1,000 person-years at ages 2-9 years. The mortality rate was significantly lower among children of foreign-born mothers and was significantly higher among preterm infants with low birth weight. The mortality rates were not significantly higher for infants after 28 days with sickle cell disease than for all New York births, but they were 2.7-8.4 times higher for children 1 through 9 years old with homozygous sickle cell disease than for those of all non-Hispanic black or Hispanic children born to New York residents.

CONCLUSION

Estimated mortality risk in children with homozygous sickle cell disease remains elevated even after adjustment for maternal race/ethnicity. These results provide evidence regarding the current burden of child mortality among children with sickle cell disease despite newborn screening.Genet Med 17 6, 452-459.

Factors associated with survival in a contemporary adult sickle cell disease cohort

In this study, the relationship of clinical differences among patients with sickle cell disease (SCD) was examined to understand the major contributors to early mortality in a contemporary cohort. Survival data were obtained for 542 adult subjects who were enrolled since 2002 at three university hospitals in the southeast United States. Subjects were followed up for a median of 9.3 years. At enrollment, clinical parameters were collected, including hemoglobin (Hb) genotype, baseline laboratory values, comorbidities, and medication usage. Levels of soluble adhesion molecules were measured for a subset of 87 subjects. The relationship of clinical characteristics to survival was determined using regression analysis. Median age at enrollment was 32 years. Median survival was 61 years for all subjects. Median survival for Hb SS and Sβ(0) was 58 years and for Hb SC and Sβ(+) was 66 years. Elevated white blood count, lower estimated glomerular filtration rate, proteinuria, frequency of pain crises, pulmonary hypertension, cerebrovascular events, seizures, stroke, sVCAM-1, and short-acting narcotics use were significantly associated with decreased survival. Forty-two percent of subjects were on hydroxyurea therapy, which was not associated with survival. SCD continues to reduce life expectancy for affected individuals, particularly those with Hb Sβ(0) and SS. Not only were comorbidities individually associated with decreased survival but also an additive effect was observed, thus, those with a greater number of negative endpoints had worse survival (P < 0.0001). The association of higher sVCAM-1 levels with decreased survival suggests that targeted therapies to reduce endothelial damage and inflammation may also be beneficial.

Top-down proteomics and direct surface sampling of neonatal dried blood spots: diagnosis of unknown hemoglobin variants

We have previously shown that liquid microjunction surface sampling of dried blood spots coupled with high resolution top-down mass spectrometry may be used for screening of common hemoglobin variants HbS, HbC, and HbD. In order to test the robustness of the approach, we have applied the approach to unknown hemoglobin variants. Six neonatal dried blood spot samples that had been identified as variants, but which could not be diagnosed by current screening methods, were analyzed by direct surface sampling top-down mass spectrometry. Both collision-induced dissociation and electron transfer dissociation mass spectrometry were employed. Four of the samples were identified as β-chain variants: two were heterozygous Hb D-Iran, one was heterozygous Hb Headington, and one was heterozygous Hb J-Baltimore. The fifth sample was identified as the α-chain variant heterozygous Hb Phnom Penh. Analysis of the sixth sample suggested that it did not in fact contain a variant. Adoption of the approach in the clinic would require speed in both data collection and interpretation. To address that issue, we have compared manual data analysis with freely available data analysis software (ProsightPTM). The results demonstrate the power of top-down proteomics for hemoglobin variant analysis in newborn samples.

Frequently asked questions by hospitalists managing pain in adults with sickle cell disease

Pain is the predominant medical presentation to hospitalists for patients with sickle cell disease (SCD). Dramatic treatment gains of SCD in childhood have resulted in more adults now requiring hospitalization than children. This has created new challenges to improve the quality of hospital care for SCD. The evidence base for pain management in SCD is lacking. We therefore offer some evidence and our informed opinion to answer frequently asked questions (FAQs) about pain management by hospitalists caring for adults with SCD. The most common questions center around defining a crisis; selecting and managing opioids; distinguishing between opioid tolerance, physical dependence, and addiction or misuse; determining appropriateness of discharge; and avoiding lengthy or recurrent hospitalizations.

A review of the literature on the multiple dimensions of chronic pain in adults with sickle cell disease

Sickle cell disease (SCD) is a major health care and societal problem that affects millions of people worldwide. In Nigeria, 45,000 to 90,000 babies are born each year with SCD. In the United States, SCD is the most common genetic disorder, affecting more than 80,000 people, the majority of whom are African American. Sickle cell pain is the hallmark feature of SCD. Most of the research on pain from SCD has focused on children with acute pain associated with sickle cell crisis. Consequently, very little is known about the occurrence and characteristics of chronic pain, especially in adults with SCD. Individuals with SCD who experience chronic pain are often underserved, and their pain is undertreated. This undertreatment may result in millions of dollars per year spent on emergency room visits, hospitalizations, and lost work productivity. The primary purpose of this literature review was to summarize the findings from studies that evaluated the characteristics of chronic pain in adults with SCD. Each of the studies included in this review was evaluated to determine if it provided data on the following multidimensional characteristics of chronic pain: occurrence, number of pain episodes, duration, pattern, quality, location, intensity, aggravating factors, relieving factors, and impact of pain on function. A secondary purpose was to identify gaps in knowledge and directions for future research on the multiple dimensions of chronic pain in adults with SCD.

Sickle cell disease in the United States: looking back and forward at 100 years of progress in management and survival

The past 100 years since James Herrick's first description of sickle cell disease in the United States have been characterized by the gradual development of management strategies. We review the progress in sickle cell disease management in the United States over the past 100 years, with emphasis on the diverse forces surrounding advances in disease management. Mortality and survival data are presented chronologically, with an attempt to highlight improvements in survival associated with specific advancements for pediatric and adult care. Finally, the future course for sickle cell disease management is explored, given the continued work in advancing the field.

Emergency department visits made by patients with sickle cell disease: a descriptive study, 1999-2007

BACKGROUND

Patients with sickle cell disease (SCD) often use emergency department services to obtain medical care. Limited information is available about emergency department use among patients with SCD.

PURPOSE

This study assessed characteristics of emergency department visits made nationally by patients with SCD.

METHODS

Data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) for the years 1999-2007 were analyzed. The NHAMCS is a survey of hospital emergency department and outpatient visits. Emergency department visits by patients with SCD were identified using ICD-9-CM codes, and nationally weighted estimates were calculated.

RESULTS

On average, approximately 197,333 emergency department visits were estimated to have occurred each year between 1999 and 2007 with SCD as one of the diagnoses listed. The expected source of payment was private insurance for 14%, Medicaid/State Children's Health Insurance Program for 58%, Medicare for 14%, and other/unknown for 15%. Approximately 29% of visits resulted in hospital admission; this was 37% among patients aged 0-19 years, and 26% among patients aged >/=20 years. The episode of care was indicated as a follow-up visit for 23% of the visits. Patient-cited reasons for the emergency department visit included chest pain (11%); other pain or unspecified pain (67%); fever/infection (6%); and shortness of breath/breathing problem/cough (5%), among other reasons.

CONCLUSIONS

Substantial numbers of emergency department visits occur among people with SCD. The most common reason for the emergency department visits is pain symptoms. The findings of this study can help to improve health services delivery and utilization among patients with SCD.

Cardiopulmonary complications leading to premature deaths in adult patients with sickle cell disease

Sickle cell disease (SCD) is associated with early mortality. We sought to determine the incidence, cause, and risk factors for death in an adult population of patients with SCD. All patients aged >/=18 years seen at the Adult Sickle Cell Center at Duke University Medical Center between January 2000 and April 2005 were enrolled. Forty-three patients (21 males and 22 females) died during the study period. The median age of survival was 39 years for females (95% CI: 34-56), 40 years for males (95% CI: 34-48), and 40 years overall (95% CI: 35-48). Cardiac causes of death accounted for 25.6% (11/43 patients); pulmonary, 14.0% (six patients); other SCD related, 32.6% (14 patients); unknown, 14.0% (six patients); and others, 14.0% (six patients). Pulseless electrical activity arrest, pulmonary emboli, multiorgan failure, and stroke were the most frequent causes of death. Among the deceased patients, the most common premorbid conditions were cardiopulmonary: acute chest syndrome/pneumonia (58.1%), Pulmonary hypertension (pHTN; 41.9%), systemic HTN (25.6%), congestive heart failure (25.6%), myocardial infarction (20.9%), and arrhythmias (14.0%). Tricuspid regurgitant jet velocity was significantly higher (3.1 m/sec vs. 2.6 m/sec, P < 0.001) and hemoglobin significantly lower (8.3 g/dL vs. 9.2 g/dL, P < 0.05) in deceased patients when compared with patients who lived, respectively. With improved preventive and therapeutic advances, including hydroxyurea therapy, acute complications such as infection are no longer the leading cause of death; instead, causes of death and premorbid conditions are shifting to chronic cardiopulmonary complications. Further, arrhythmia leading to premature death is under-recognized in SCD and warrants further investigation.

A novel human gamma-globin gene vector for genetic correction of sickle cell anemia in a humanized sickle mouse model: critical determinants for successful correction

We show that lentiviral delivery of human gamma-globin gene under beta-globin regulatory control elements in hematopoietic stem cells (HSCs) results in sufficient postnatal fetal hemoglobin (HbF) expression to correct sickle cell anemia (SCA) in the Berkeley "humanized" sickle mouse. Upon de-escalating the amount of transduced HSCs in transplant recipients, using reduced-intensity conditioning and varying gene transfer efficiency and vector copy number, we assessed critical parameters needed for correction. A systematic quantification of functional and hematologic red blood cell (RBC) indices, organ pathology, and life span was used to determine the minimal amount of HbF, F cells, HbF/F-cell, and gene-modified HSCs required for correcting the sickle phenotype. We show that long-term amelioration of disease occurred (1) when HbF exceeded 10%, F cells constituted two-thirds of the circulating RBCs, and HbF/F cell was one-third of the total hemoglobin in sickle RBCs; and (2) when approximately 20% gene-modified HSCs repopulated the marrow. Moreover, we show a novel model using reduced-intensity conditioning to determine genetically corrected HSC threshold that corrects a hematopoietic disease. These studies provide a strong preclinical model for what it would take to genetically correct SCA and are a foundation for the use of this vector in a human clinical trial.

Trends in pediatric sickle cell disease-related mortality in the United States, 1983-2002

OBJECTIVE

To analyze trends in sickle cell disease (SCD)-related mortality among black children during 1983-2002.

STUDY DESIGN

Using the multiple-cause mortality files compiled by the Centers for Disease Control and Prevention's National Center for Health Statistics, we analyzed deaths among children classified as black who were age 14 years and younger and had SCD identified on their death certificates.

RESULTS

Relative to the rate for 1983-1986, the SCD mortality rate for 1999-2002 decreased by 68% (95% confidence interval [CI]=58% to 75%) at age 0 to 3 years, by 39% (95% CI=16% to 56%) at age 4 to 9 years, and by 24% (95% CI= -9% to 47%) at age 10 to 14 years. For the most recent period studied, a significant (42%) reduction in mortality at age 0 to 3 years was seen between 1995-1998 and 1999-2002, with essentially no reduction in SCD mortality at older ages.

CONCLUSIONS

Recent decreases in SCD mortality in black children under age 4 years coincided with the introduction of the 7-valent pneumococcal conjugate vaccine in 2000, although temporal association is not evidence of causation. The lack of significant recent reduction in SCD mortality in older children indicates the need for new treatment approaches.

Impact of proximity to comprehensive sickle cell center on utilization of healthcare services among children with sickle cell disease

BACKGROUND

The impact of comprehensive care on utilization of healthcare services by children with sickle cell disease (SCD) has not been fully evaluated. We compared the medical care utilization and mortality in children less than 20 years of age with SCD in four regions in the state of Tennessee with and without a comprehensive sickle cell center (CSCC).

METHODS

Rates of hospitalizations, outpatient and emergency department (ED) visits, and deaths were measured in a cohort of children aged <20 years with SCD, enrolled in TennCare, from January 1995 to December 2002. TennCare data linked to Tennessee vital records were used to define the population and identify the outcomes. The patients were classified into one of four regions based on their residential address on the day of their hospitalization or outpatient visit.

RESULTS

The cohort consisted of 1,214 children with 6,393 person-years of follow-up. Fifty-six percent of patients resided in the region with the CSCC. This region had the highest overall rates of hospitalization for all children (P < 0.001), while ED and outpatient visits were higher in other areas. The death rates ranged from 1.8 to 4.3 per 1,000 person-years in the four regions and did not represent statistically significant differences.

CONCLUSION

No clear pattern of improved utilization of medical care services were identified in relation to proximity of residence to a CSCC. This cohort was not large enough to detect small differences in death rates. In addition, other outcomes that incorporate quality of life measures may be more sensitive to differences in medical care.

Sickle cell disease: a question of equity and quality

Thirty years ago, the first major federal legislation concerning sickle cell disease treatment was passed, resulting in the development of comprehensive sickle cell centers. We are now at another watershed moment in the treatment of this illness with the passage in October 2004 of the Sickle Cell Treatment Act, designed to substantially expand specialized sickle cell treatment programs. This legislation offers a remarkable opportunity to significantly improve health outcomes for individuals with sickle cell disease if it is implemented with a specific focus on the distinct but related issues of equity and quality. Despite major advances in sickle cell disease treatment that have occurred over the past 3 decades, important gaps exist both in the equity of government and private philanthropic support for research and in the uniform provision of high quality clinical care. This article assesses the current gaps in funding support and in the implementation of improvements in clinical care in order to suggest strategies for making optimal use of the opportunity that the new legislation presents to improve the health of all individuals affected by this disease.

Medical care utilization and mortality in sickle cell disease: a population-based study

The purpose of this study was to evaluate the pattern of medical care utilization and mortality in children and adults with sickle cell disease (SCD) in the state of Tennessee. Rates of hospitalization, emergency department visits, and deaths were measured in a cohort of adults and children with SCD enrolled in TennCare, Tennessee's Medicaid managed health care program, from January 1995 to December 2002. TennCare data linked to Tennessee vital records were used to define the population and identify the outcomes. For children less than 5 years of age, the mortality rate was similar to that of other black Tennessee children (P = 0.71). Among children, the death rate was highest in 10-19 years of age and was 8-fold higher than Tennessee's race- and age-specific rate. Among 20- to 49-year-old patients with SCD, mortality was significantly higher in males than in females (P < 0.001). As compared to the black population without SCD in TennCare, patients with SCD had 7-30 times higher rate of hospitalization and 2-6 times higher rates of emergency department visits (P < 0.001). The death rate in adolescents and young adults with SCD continues to be much higher than population-specific rates. Interventions to prevent morbidity and mortality related to SCD are urgently needed.

Outcome of sickle cell anemia: a 4-decade observational study of 1056 patients

Based on a prospective cohort study of 1056 patients with sickle cell anemia (Hb SS) initiated in 1959, we investigated the influence of calendar era, age, sex, and prior medical conditions on the subsequent development of irreversible organ damage and survival using the Cox regression model with time-dependent covariates adjusting for all prior occurrences. We studied 30 acute clinical events, and focused on 8 prototypic forms of irreversible organ damage. Childhood survival to age 20 years has improved from 79% for those born before 1975 to 89% for children born in or after 1975. Bone infarction was a significant risk factor for avascular necrosis (p = 0.01), and infantile dactylitis was a significant risk factor for stroke (p = 0.01). Prior hospitalized vaso-occlusive sickle crisis in adults was significantly associated with the increased rate of avascular necrosis (p < 0.001), leg ulcers (p < 0.001), sickle chronic lung disease (p < 0.001), renal failure (p < 0.005), and early death (p < 0.001). The diagnosis of clearly evident clinical conditions such as leg ulcer, osteonecrosis, and retinopathy predicted an increased likelihood of developing a more lethal form of organ damage and earlier death: 77% of patients with chronic lung disease, 75% of those with renal insufficiency, and 51% of those with stroke had a prior chronic condition. Of the 232 patients who died, 73% had 1 or more clinically recognized forms of irreversible organ damage. By the fifth decade, nearly one-half of the surviving patients (48%) had documented irreversible organ damage. End-stage renal disease (glomerulosclerosis), chronic pulmonary disease with pulmonary hypertension, retinopathy, and cerebral microinfarctions are manifestations of arterial and capillary microcirculation obstructive vasculopathy. The current study underscores the need for preventive therapy to ameliorate the progression of the sickle vasculopathy.

Understanding pain and improving management of sickle cell disease: the PiSCES study

Until recent decades, sickle cell disease (SCD) was associated with recurrent, disabling pain, organ failure and death in childhood or early adulthood. SCD treatment advances have now decreased pain and prolonged survival, but episodic or chronic pain may still require substantial analgesic use and frequent hospitalization for pain episodes. This pain is poorly characterized and often poorly treated. Adult patients may face barriers to comprehensive SCD care, stigmatization of their care-seeking behavior by providers and lack of family support, forcing them into maladaptive coping strategies. The Pain in Sickle Cell Epidemiology Study (PiSCES) attempts to develop and validate a biopsychosocial model of SCD pain, pain response and healthcare utilization in a large, multisite adult cohort. PiSCES participants complete a baseline survey and six months of daily pain diaries in which they record levels of SCD-related pain and related disability and distress as well as responses to pain (e.g., medication use, hospital visits). PiSCES will advance methods of measuring pain and pain response in SCD by better describing home-managed as well as provider-managed pain. PiSCES will assess the relative contributions of biological (disease-related), psychosocial and environmental (readiness to utilize) factors to overall pain and pain response in SCD, suggesting targets for biobehavioral interventions over time. Importantly, PiSCES will also identify "triggers" of SCD pain episodes and healthcare utilization in the moment of pain, suggesting targets for timely care that mutes pain episodes.

Survival of children with sickle cell disease

Contemporary survival data are not available for children with sickle cell disease (SCD). The few previous childhood SCD cohort studies do not reflect the benefits of modern therapy. We defined an inception cohort of newborns with sickle cell anemia (SS), sickle-beta degrees -thalassemia (S beta degrees ), sickle-hemoglobin C disease (SC), or sickle-beta(+)-thalassemia (Sbeta(+)) who were identified by newborn screening and followed for up to 18 years. The incidence of death and stroke were calculated. Overall survival, SCD-related survival (considering only SCD-related deaths), and strokefree survival were determined. The 711 subjects provided 5648 patient-years of observation. Twenty-five subjects died; mean age at death was 5.6 years. Five patients died from infection. Thirty had at least one stroke. Among SS and Sbeta degrees subjects (n = 448), the overall rates of death and stroke were 0.59 and 0.85/100 patient-years. Survival analysis of SS and Sbeta degrees subjects predicted the cumulative overall, SCD-related, and stroke-free survival to be 85.6%, 93.6%, and 88.5% by 18 years of age. No SCD-related deaths or strokes occurred in SC or Sbeta(+) subjects (n = 263). Childhood mortality from SCD is decreasing, the mean age at death is increasing, and a smaller proportion of deaths are from infection.

Outcome in hemoglobin SC disease: a four-decade observational study of clinical, hematologic, and genetic factors

Over the past 40 years, we observed 284 subjects with hemoglobin SC disease (Hb SC) for 2,837 person-years. We examined the association of the course of clinical events with hematologic and genetic factors. The mean entry age was 21 years, although 15% entered before one year of age. The mean Hb concentration was 11.3 g/dL, the mean fetal hemoglobin was 2.5%, and the mean MCV was 84.4 fL. Twenty-five subjects died at a median age of 37 years. Chronic organ-specific complications occurred in 112 subjects (39.4%), with advanced retinopathy in 65 subjects (22.9%) and osteonecrosis (avascular necrosis) in 42 subjects (14.8%). We identified the beta-globin haplotypes in 82 subjects and the alpha-gene status in 79. Twenty-nine percent had alpha-thalassemia-2. The beta(CI) haplotype was present in 85.4%. We found a decreased incidence of retinopathy in the beta(CI) subjects compared to the non-beta(CI) subjects (33% vs. 67%; P = 0.049) with a later mean onset age (29 years vs. 21 years; log-rank test, P= 0.026). We also found a consistent pattern of decreased morbidity in subjects who had alpha-thalassemia-2 in comparison to those who did not. We found a reduced risk of chronic organ-specific complications (log-rank test, P= 0.003), lower incidence of sickle crisis (48% vs. 80%, P= 0.001), later onset of gallbladder disease (age of onset: 55 years vs. 34 years; P= 0.055), and lower risk of osteonecrosis (log-rank test, P= 0.024). Our findings suggest that Hb SC subjects who have not inherited alpha-thalassemia-2 might benefit from erythrocyte rehydration therapy.

Location of death in Canada. A comparison of 20th-century hospital and nonhospital locations of death and corresponding population trends

This report compares 20th-century Canadian hospital and nonhospital location-of-death trends and corresponding population mortality trends. One of the chief findings is a hospitalization-of-death trend, with deaths in hospital peaking in 1994 at 80.5% of all deaths. The rise in hospitalization was more pronounced in the years prior to the development of a national health care program (1966). Another key finding is a gradual reduction since 1994 in hospital deaths, with this reduction occurring across all sociodemographic variables. This suggests nonhospital care options are needed to support what may be an ongoing shift away from hospitalized death and dying.

Neuropsychological aspects of pediatric sickle cell disease

Sickle cell disease (SCD), a class of genetic disorders characterized by abnormal, sickled red blood cells, is a chronic illness that results in progressive cerebrovascular disease. Neurocognitive sequelae of clinically apparent cerebrovascular accidents in children with SCD are characterized by pervasive impairments, including decrements in general intellectual functioning, language and verbal abilities, visual-motor and visual-spatial processing, memory, academic achievement, and processing of subtle prosodic information. In contrast, subtle neurocognitive deficits in the areas of attention and concentration, executive function, and visual-motor speed and coordination appear to be associated with silent infarcts that are not necessarily detected on physical examination. Investigation of the disease course and associated neurocognitive sequelae suggest a disease-specific model of neuropsychological impairment. Recommendations are made for clinical and research efforts in the field of pediatric neuropsychology.

Reliability of isoelectrofocusing for the detection of Hb S, Hb C, and HB D in a pioneering population-based program of newborn screening in Brazil

Out of 128,326 newborns in the first 6-month period of a population-based screening program in Minas Gerais, Brazil, a second sample was obtained at the age of 6 months from 4,635 carriers of Hbs AS, AC, and AD which were detected by isoelectrofocusing. Discordance in results occurred in only 27 cases (0.6%): in seven there was a history of hemotransfusion; errors during pipetting or transcription of results occurred in seven cases; it was difficult to differenciate between Hbs S and D in eight patients; and the causes were not elucidated in five patients. The incidence of Hbs FS and FSC for the total population was 1:2,800 and 1:3,450, respectively. Isoelectrofocusing is a very reliable method for distinguishing AS, AC, or AD carriers from patients presenting with [corrected] variant hemoglobin and beta(+)-thalassemia combinations, and may be widely used in massive newborn screening programs.

Sickle cell anemia

Sickle cell anemia (SCA) is a disease caused by production of abnormal hemoglobin, which binds with other abnormal hemoglobin molecules within the red blood cell to cause rigid deformation of the cell. This deformation impairs the ability of the cell to pass through small vascular channels; sludging and congestion of vascular beds may result, followed by tissue ischemia and infarction. Infarction is common throughout the body in the patient with SCA, and it is responsible for the earliest clinical manifestation, the acute pain crisis, which is thought to result from marrow infarction. Over time, such insults result in medullary bone infarcts and epiphyseal osteonecrosis. In the brain, white matter and gray matter infarcts are seen, causing cognitive impairment and functional neurologic deficits. The lungs are also commonly affected, with infarcts, emboli (from marrow infarcts and fat necrosis), and a markedly increased propensity for pneumonia. The liver, spleen, and kidney may experience infarction as well. An unusual but life-threatening complication of SCA is sequestration syndrome, wherein a considerable amount of the intravascular volume is sequestered in an organ (usually the spleen), causing vascular collapse; its pathogenesis is unknown. Finally, because the red blood cells are abnormal, they are removed from the circulation, resulting in a hemolytic anemia. For the patient with SCA, however, the ischemic complications of the disease far outweigh the anemia in clinical importance.

Safety and immunogenicity of heptavalent pneumococcal vaccine conjugated to CRM(197) among infants with sickle cell disease. Pneumococcal Conjugate Vaccine Study Group

OBJECTIVES

To determine the immunogenicity and safety of heptavalent pneumococcal polysaccharide vaccine (serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F) conjugated to CRM(197) (7-valent conjugate pneumococcal vaccine [7VPnC]) among infants with sickle cell disease (SCD) and a comparison group of infants without SCD (non-SCD).

DESIGN

Two cohorts of infants were enrolled and received open-label doses of 7VPnC vaccine; infants enrolled before 2 months of age received 7VPnC vaccine at 2, 4, and 6 months of age followed by 23-valent pneumococcal polysaccharide vaccine (PS-23) at 24 months of age for those infants with SCD (schedule A), and infants enrolled between 2 and 12 months of age received 7VPnC at 12 months of age followed by PS-23 at 24 months of age for infants with SCD (schedule B). Safety data were collected for 3 days after each dose of vaccine. Antibody concentrations were measured to each of the 7VPnC serotypes by enzyme-linked immunosorbent assay before each vaccine dose and 1 month after the last 7VPnC dose and the PS-23 vaccine dose.

RESULTS

Forty-five infants (34 SCD and 11 non-SCD) were vaccinated according to schedule A and 16 infants (13 SCD and 3 non-SCD) according to schedule B. The 7VPnC vaccine was highly immunogenic for all serotypes among infants with and without SCD who received 3 doses of vaccine according to schedule A: depending on serotype, 89% to 100% achieved antibody concentrations above.15 microg/mL and 56% to 100% achieved antibody concentrations above 1.0 microg/mL. Among infants immunized according to schedule B, a single dose of 7VPnC vaccine resulted in antibody concentrations above.15 microg/mL in 53% to 92% by serotype and above 1.0 microg/mL in 31% to 71% by serotype. A single dose of PS-23 resulted in dramatic increases in the antibody concentrations to all serotypes regardless of 1- or 3-dose priming. There was no difference in the reactogenicity of the 7VPnC vaccine between those with and without SCD. There were no serious reactions to the 7VPnC or PS-23 vaccines, even among those with high antibody concentrations before immunization.

CONCLUSIONS

Infants with SCD respond to 7VPnC vaccine with antibody concentrations that are at least as high as infants without SCD. Infants immunized with 7VPnC vaccine at 2, 4, and 6 months of age developed antibody concentrations in the same range as those achieved among infants without SCD enrolled in a large trial that demonstrated vaccine efficacy against invasive disease. Significant rises were seen in antibody concentrations to all 7VPnC serotypes after the PS-23 booster in children receiving schedule A or B.

Current knowledge in the management of children and adolescents with sickle cell disease: Part 1, Physiological issues

This article reviews the current state of the knowledge in the management of children and adolescents with sickle cell disease (SCD). A thorough review of the literature concerning physiological issues including the clinical manifestations of SCD as well as current treatment modalities is included. Therapeutic management of health and illness for a child with SCD is discussed in relation to primary, secondary, and tertiary prevention. Recommendations for nursing practice and research are made.

Preventing morbidity and mortality from sickle cell disease. A public health perspective

CONTEXT

Sickle cell disease is a group of conditions characterized by production of abnormal hemoglobin, with clinical manifestations that vary by genotype and age.

OBJECTIVE

To discuss current public health issues associated with sickle cell disease, and approaches to preventing complications from these conditions in the United States.

DESIGN

Literature review.

RESULTS

Most clinical interventions for people with sickle cell disease discussed in the medical literature can be classified as tertiary prevention: for example, therapy to ameliorate anemia, reduce the frequency of pain crises, or prevent stroke recurrences. A form of secondary prevention, newborn screening, has emerged as an important public health approach to identifying affected children before they develop complications. Newborn screening is the starting point for simple public health strategies such as parental education, immunization, and penicillin prophylaxis. Identification of affected families by newborn or community screening programs has also been an entry point for genetic counseling, although utilization of prenatal testing has varied by factors such as geographic location. Public health agencies have had significant involvement with funding, policy making, and formulation of laboratory and clinical guidelines for sickle cell disease. Since the introduction of penicillin prophylaxis policies, newborn screening, new immunizations, and comprehensive medical care centers, the survival of young children with sickle cell disease has improved.

CONCLUSIONS

Although the efforts of preventive medicine providers in public health programs are not solely responsible for the improved survival of children with sickle cell disease, such programs remain an important component in preventing sickle cell complications.