Barriers and Facilitators to Implementing an Evidence-Based Community Health Worker Model

Importance

Community health worker (CHW) programs may improve health outcomes, increase quality of life, and reduce hospitalizations and cost of care. However, knowledge is limited on the barriers and facilitators associated with scaling evidence-based CHW programs to maximize their public health outcomes.

Objective

To identify barriers and facilitators to implementing an evidence-based CHW model.

Design, Setting, and Participants

This qualitative study examined perspectives of Individualized Management of Person-Centered Targets (IMPaCT) program staff (health system leaders, program managers, and community health workers) and patients receiving the intervention between March 9, 2020, and July 22, 2021, at 5 institutionally and geographically diverse health systems across the US. The collected data were analyzed between December 1, 2021, and April 27, 2022. Program staff were recruited via purposive sampling, and patients were recruited via convenience sampling.

Intervention

The disease-agnostic IMPaCT CHW model includes a standardized implementation approach and a structured set of theory-informed intervention components to create and achieve individualized action plans.

Main Outcomes and Measures

Interview guides were informed by the Consolidated Framework for Implementation Research. A rapid qualitative analytic technique was used to identify key themes, which were categorized into barriers and facilitators associated with framework ecological domains.

Results

Of a total 41 individuals invited, 39 agreed to participate (95% response rate; mean [SD] age, 45.0 [12.6] years; 30 women). General barriers included economic and policy constraints, including insufficient funding for CHW programs, clinical integration challenges, and CHW difficulty with maintaining boundaries. Program-specific barriers included insufficiently tailored materials for certain populations and upfront and ongoing program costs. General facilitators included CHWs' interpersonal skills and life experiences. Program-specific facilitators included the model's strong evidence base, supportive implementation team, and program design that enabled relationship building and engagement. Additional themes were cited as both barriers and facilitators, including the COVID-19 pandemic, organizational leadership, IMPaCT training, and program fidelity.

Conclusions and Relevance

These findings suggest growing recognition of the importance of CHWs to improving health equity and population health. Barriers identified point to important policy and practice implications for CHW programs more broadly, including the need for continued attention to improving clinical integration and the need for sustainable program financing to preserve the longevity of this workforce.

Community Health Worker Integration with and Effectiveness in Health Care and Public Health in the United States

Community health workers (CHWs) have worked in a variety of settings in the United States for more than 70 years and are increasingly recognized as an essential health workforce. CHWs share life experience with the people they serve and have firsthand knowledge of the causes and impacts of health inequity. They provide a critical link between marginalized communities and health care and public health services. Several studies have demonstrated that CHWs can improve the management of chronic conditions, increase access to preventive care, improve patients' experience of care, and reduce health care costs. CHWs can also advance health equity by addressing social needs and advocating for systems and policy change. This review provides a history of CHW integration with health care in the United States; describes evidence of the impact of CHW programs on population health, experience, costs of care, and health equity; and identifies considerations for CHW program expansion.

Digital Health and Community Health Worker Support for Diabetes Management: a Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate the effectiveness of a digital health intervention plus community health worker (CHW) support on self-monitoring of blood glucose and glycosylated hemoglobin (HbA1c) among adult Medicaid beneficiaries with diabetes.

DESIGN

Randomized controlled trial.

SETTING

Urban outpatient clinic.

PARTICIPANTS

Adult Medicaid beneficiaries living with diabetes and treated with insulin and who had a HbA1c ≥ 9%.

INTERVENTION

Participants were randomly assigned to one of three arms. Participants in the usual-care arm received a wireless glucometer if needed. Those in the digital arm received a lottery incentive for daily glucose monitoring. Those in the hybrid arm received the lottery plus support from a CHW if they had low adherence or high blood glucose levels.

MAIN MEASURES

The primary outcome was the difference in adherence to daily glucose self-monitoring at 3 months between the hybrid and usual-care arms. The secondary outcome was difference in HbA1c from baseline at 6 months.

KEY RESULTS

A total of 150 participants were enrolled in the study. A total of 102 participants (68%) completed the study. At 3 months, glucose self-monitoring rates in the hybrid versus usual-care arms were 0.72 vs 0.65, p = 0.23. At 6 months, change in HbA1c in the hybrid versus usual-care arms was - 0.74% vs - 0.49%, p = 0.69.

CONCLUSION

There were no statistically significant differences between the hybrid and usual care in glucose self-monitoring adherence or improvements in HbA1C.

TRIAL REGISTRATION

This trial is registered with clinicaltrials.gov identifier: NCT03939793.

Utilization and Expenditures of High-Need, High-Cost Older Adults With Disabilities

The factors that lead people to have high needs for care can vary greatly, with implications for the best approaches to serving their needs. One high need group of interest is older adults with disabilities and multiple comorbidities. There is variation in need within this group. Of particular interest is the subset that is both high need and high cost (HNHC). We present work describing Medicare and Medicaid utilization and expenditures for this high need group and the HNHC subset. Over 7.6 million people were identified as high need; 13.6% of them also were defined as HNHC. Patterns of utilization differed between these groups, with the HNHC group more likely to use inpatient care and nursing home care, but less likely to use community-based long-term services and supports. These findings have implications for the development of care models that might best meet the needs of this population.

Impact of a Web-based Information and Referral Tool on Access to Federal and State Programs for Older Adults

Federal and state governments provide a plethora of benefits programs intended to help older Americans, but take-up rates for the programs is low. BenefitsCheckUp® is an online tool intended to increase enrollment in these programs. To evaluate the impact of this national online screening tool providing individualized benefit information, we conducted a web survey of individuals who screened potentially eligible for programs including Supplemental Security Income, Medicaid, Medicare Savings Programs, Supplemental Nutrition Assistance Program, and energy assistance. Thirty-six percent of those surveyed applied for at least one benefit at an annualized, estimated average value of $2,865, and 20.5% enrolled, representing about 7% of the approximately 2 million site visitors age 60+. These results indicate that an online screening tool is a promising strategy for increasing benefit take-up rates among older adults with the value of benefits received far exceeding investments.

Loss Of SNAP Is Associated With Food Insecurity And Poor Health In Working Families With Young Children

The Supplemental Nutrition Assistance Program (SNAP) helps working families meet their nutritional needs. Families whose earned income increases in a given month may have their SNAP benefits abruptly reduced or cut off in the following month. Using sentinel sample data from 2007-15 for families with children younger than age four, we investigated how SNAP benefit reductions or cutoffs resulting from increased income were related to economic hardships (food and energy insecurity, unstable housing, forgone health and/or dental care, and health cost sacrifices) and to caregiver and child health. After we controlled for covariates, we found that the groups whose SNAP benefits were reduced or cut off had significantly increased odds of household and child food insecurity, compared to a group with consistent participation in SNAP. Reduced benefits were associated with 1.43 and 1.22 times greater odds of fair or poor caregiver and child health, respectively. Policy modifications to smooth changes in benefit levels as work incomes improve may protect working families with young children from increased food insecurity, poor health, and forgone care.

The Intergenerational Circumstances of Household Food Insecurity and Adversity

Household food insecurity is linked with exposure to violence and adversity throughout the life course, suggesting its transfer across generations. Using grounded theory, we analyzed semistructured interviews with 31 mothers reporting household food insecurity where participants described major life events and social relationships. Through the lens of multigenerational interactions, 4 themes emerged: (1) hunger and violence across the generations, (2) disclosure to family and friends, (3) depression and problems with emotional management, and (4) breaking out of intergenerational patterns. After describing these themes and how they relate to reports of food insecurity, we identify opportunities for social services and policy intervention.

"Do You Wanna Breathe or Eat?": Parent Perspectives on Child Health Consequences of Food Insecurity, Trade-Offs, and Toxic Stress

OBJECTIVES

This study among 51 parents of young children under age four investigated how parents that report marginal, low and very low food security characterize how trade-offs associated with food insecurity affect parents' mental health and child well-being.

METHODS

We carried out 51 semi-structured audio-recorded interviews after participants responded to a survey regarding food security status and maternal depressive symptoms. Each interview was transcribed. Through a content analysis, we coded "meaning units" in each manuscript and organized them by themes in ATLAS.ti. Among participants reporting both food insecurity and depressive symptoms, we identified three primary areas of concern: trade-offs, mental health, and child well-being.

RESULTS

Parents described how trade-offs associated with food insecurity have a profound relationship with their mental health and home environment that strongly affects young children. Descriptions of hardships include anxiety and depression related to overdue bills and shut-off notices, strains with housing costs, and safety. Parents described how their own frustration, anxiety, and depression related to economic hardship have a negative impact on their children's physical health, and their social and emotional development.

CONCLUSIONS

Parents in food insecure households recognize that trade-offs between food and other basic necessities are associated with their personal stress and poor mental health that, in turn, affects their children's health and development. Partnerships between healthcare providers, policymakers, and parents are essential to successfully address and prevent the poor child health outcomes of toxic stress associated with food insecurity and poverty.

Childhood Adversity and Adult Reports of Food Insecurity Among Households With Children

INTRODUCTION

Exposure to childhood adversity, including abuse, neglect, and household dysfunction, is associated with negative long-term health and economic outcomes. Little is known about how adversity exposure in parents' early lives may be related to later food insecurity for parents and their children. This study investigated the association between female caregivers' adverse childhood experiences (ACEs) and household and child food insecurity, taking into account depressive symptoms.

METHODS

This study used cross-sectional data from 1,255 female caregivers of children aged <4 years surveyed in an urban clinical setting from March 2012 through June 2014. Measures included sociodemographic characteristics; caregivers' ACEs, including abuse, neglect, and household dysfunction; depressive symptoms; and household and child food insecurity. Multinomial and logistic regression analyses assessed the relationship among ACEs, depressive symptoms, and household and child food security status.

RESULTS

Caregiver depressive symptoms modified associations between ACEs and food insecurity level. After adjusting for covariates, caregivers reporting both depressive symptoms and four or more ACEs were 12.3 times as likely to report low food security (95% CI=6.2, 24.7); 28.8 times as likely to report very low food security (95% CI=12.8, 64.8); and 17.6 times as likely to report child food insecurity (95% CI=7.3, 42.6) compared with those reporting no depressive symptoms and no ACEs.

CONCLUSIONS

Depressive symptoms and ACEs were independently associated with household and child food insecurity, and depressive symptoms modified the association between ACEs and household and child food insecurity. Comprehensive policy interventions incorporating nutrition assistance and behavioral health may address intergenerational transmission of disadvantage.

Analysis of molecular intra-patient variation and delineation of a prognostic 12-gene signature in non-muscle invasive bladder cancer; technology transfer from microarrays to PCR

Background:

Multiple clinical risk factors and genetic profiles have been demonstrated to predict progression of non-muscle invasive bladder cancer; however, no easily clinical applicable gene signature has been developed to predict disease progression independent of disease stage and grade.

Methods:

We measured the intra-patient variation of an 88-gene progression signature using 39 metachronous tumours from 17 patients. For delineation of the optimal quantitative reverse transcriptase PCR panel of markers, we used 115 tumour samples from patients in Denmark, Sweden, UK and Spain.

Results:

Analysis of intra-patient variation of the molecular markers showed 71% similar classification results. A final panel of 12 genes was selected, showing significant correlation with outcome. In multivariate Cox regression analysis, we found that the 12-gene signature was an independent prognostic factor (hazard ratio=7.4 (95% confidence interval: 3.4–15.9), P<0.001) when adjusting for stage, grade and treatment. Independent validation of the 12-gene panel and the determined cut-off values is needed and ongoing.

Conclusion:

Intra-patient marker variation in metachronous tumours is present. Therefore, to increase test sensitivity, it may be necessary to test several metachronous tumours from a patient’s disease course. A PCR-based 12-gene signature significantly predicts disease progression in patients with non-muscle invasive bladder cancer.

Multimodal communication in animals, humans and robots: an introduction to perspectives in brain-inspired informatics

Recent years have seen convergence in research on brain mechanisms and neurocomputational approaches, culminating in the creation of a new generation of robots whose artificial "brains" respect neuroscience principles and whose "cognitive" systems venture into higher cognitive domains such as planning and action sequencing, complex object and concept processing, and language. The present article gives an overview of selected projects in this general multidisciplinary field. The work reviewed centres on research funded by the EU in the context of the New and Emergent Science and Technology, NEST, funding scheme highlighting the topic "What it means to be human". Examples of such projects include learning by imitation (Edici project), examining the origin of human rule-based reasoning (Far), studying the neural origins of language (Neurocom), exploring the evolutionary origins of the human mind (Pkb140404), researching into verbal and non-verbal communication (Refcom), using and interpreting signs (Sedsu), characterising human language by structural complexity (Chlasc), and representing abstract concepts (Abstract). Each of the communication-centred research projects revealed individual insights; however, there had been little overall analysis of results and hypotheses. In the Specific Support Action Nestcom, we proposed to analyse some NEST projects focusing on the central question "What it means to communicate" and to review, understand and integrate the results of previous communication-related research, in order to develop and communicate multimodal experimental hypotheses for investigation by future projects. The present special issue includes a range of papers on the interplay between neuroinformatics, brain science and robotics in the general area of higher cognitive functions and multimodal communication. These papers extend talks given at the NESTCOM workshops, at ICANN (http://www.his.sunderland.ac.uk/nestcom/workshop/icann.html) in Porto and at the first meeting of the Federation of the European Societies of Neuropsychology in Edinburgh in 2008 (http://www.his.sunderland.ac.uk/nestcom/workshop/esn.html). We hope that the collection will give a vivid insight into current trends in the field.

History of safe use as applied to the safety assessment of novel foods and foods derived from genetically modified organisms

Very few traditional foods that are consumed have been subjected to systematic toxicological and nutritional assessment, yet because of their long history and customary preparation and use and absence of evidence of harm, they are generally regarded as safe to eat. This 'history of safe use' of traditional foods forms the benchmark for the comparative safety assessment of novel foods, and of foods derived from genetically modified organisms. However, the concept is hard to define, since it relates to an existing body of information which describes the safety profile of a food, rather than a precise checklist of criteria. The term should be regarded as a working concept used to assist the safety assessment of a food product. Important factors in establishing a history of safe use include: the period over which the traditional food has been consumed; the way in which it has been prepared and used and at what intake levels; its composition and the results of animal studies and observations from human exposure. This paper is aimed to assist food safety professionals in the safety evaluation and regulation of novel foods and foods derived from genetically modified organisms, by describing the practical application and use of the concept of 'history of safe use'.

A hotel-based outbreak of Salmonella enterica subsp. Enterica serovar Enteritidis (Salmonella Enteritidis) in the United Kingdom, 2006

An outbreak of food-borne Salmonella Enteritidis PT4 occurred in Cumbria, in north-west England, in the summer of 2006. Fifteen people, all with positive stool samples, met the case definition; three of these were admitted to hospital, including one patient who died. Preliminary investigations suggested a link to a meal served at a local hotel. A case control study was implemented, together with microbiological and environmental investigations. Fifteen microbiologically confirmed cases and 27 unmatched controls were included in the study, controls being randomly selected from people who had eaten at the hotel on the same day. The epidemiological evidence indicated a very strong association between infection and consumption of tiramisu made with raw shell eggs, although none were available for microbiological investigation. These results are in line with other salmonellosis outbreaks that have been associated with the use of raw shell eggs in food manufacturing and production.This paper highlights the continuing need for a greater awareness by those who work in the food industry of the health risks associated with the consumption of raw shell eggs.

E. coli O157 phage type 21/28 outbreak in North Cumbria associated with pasteurized milk

In March 1999, a large community outbreak of Escherichia coli O157 infection occurred in North Cumbria. A total of 114 individuals were reported to the Outbreak Control Team (OCT); 88 had laboratory confirmed E. coli O157. Twenty-eight (32%) of the confirmed cases were admitted to hospital, including three children (3.4%) with haemolytic uraemic syndrome. There were no deaths. A case-control study found that illness was strongly associated with drinking pasteurized milk from a local farm (P = <0.0001) on single variable analysis. Microbiological investigations at the farm revealed E. coli O157 phage type (PT) 21/28 VT 2 which was indistinguishable from the human isolates by pulsed field gel electrophoresis. At the time of occurrence this was the largest E. coli O157 outbreak in England and Wales and the first E. coli O157 PT 21/28 VT 2 outbreak associated with pasteurized milk. This outbreak highlights lessons to be learnt regarding on-farm pasteurization.

The contribution of epidemiology

Epidemiologic studies directly contribute data on risk (or benefit) in humans as the investigated species, and in the full food intake range normally encountered by humans. This paper starts with introducing the epidemiologic approach, followed by a discussion of perceived differences between toxicological and epidemiologic risk assessment. Areas of contribution of epidemiology to the risk assessment process are identified, and ideas for tailoring epidemiologic studies to the risk assessment procedures are suggested, dealing with data collection, analyses and reporting of both existing and new epidemiologic studies. The dietary habits and subsequent disease occurrence of over three million people are currently under observation worldwide in cohort studies, offering great potential for use in risk assessment. The use of biomarkers and data on genetic susceptibility are discussed. The paper describes a scheme to classify epidemiologic studies for use in risk assessment, and deals with combining evidence from multiple studies. Using a matrix approach, the potential contribution to each of the steps in the risk assessment process is evaluated for categories of food substances. The contribution to risk assessment of specific food substances depends on the quality of the exposure information. Strengths and weaknesses are summarized. It is concluded that epidemiology can contribute significantly to hazard identification, hazard characterisation and exposure assessment.

N-Arylsulfonylindole derivatives as serotonin 5-HT(6) receptor ligands

A series of N(1)-arylsulfonyltryptamines were found to be potent ligands of the human serotonin 5-HT(6) receptor with the 5-methoxy-1-benzenesulfonyl analogue (19) having the highest affinity. Additionally, it was discovered that a group such as 3-(3-methoxybenzyl)-1,2,4-oxadiazol-5-yl in the 2-position of the indole ring (43) can replace the arylsulfonyl substituent in the 1-position with no loss of affinity. This suggested that the binding conformation of the aminoethyl side chain at this receptor was toward the 4-position of the indole ring and was supported by the fact that the 4-(aminoethyl)indoles (45) also displayed high affinity, as did the conformationally rigid 1,3,4,5-tetrahydrobenz[c,d]indole (49). Molecular modeling showed that 19, 43, and 45 all had low-energy conformers that overlaid well onto 49. Both 19 and 49 had good selectivity over other serotonin receptors tested, with 49 also showing excellent selectivity over all dopamine receptors. In a functional adenylate cyclase stimulation assay, 19 and 49 had no agonist activity, whereas 45 behaved as a partial agonist. Finally, it was shown that 19 had good activity in the 5-HT(2A) centrally mediated mescaline-induced head twitch assay, which implies that it is brain-penetrant.

From efficacy to effectiveness: managing organisational change to improve health services for young people with deliberate self harm behaviour

Repeat Deliberate Self Harm is a recognised risk factor for completed suicide and therefore reduction by effective health service response represents a valid contribution to suicide prevention. However, only a small fraction of people with deliberate self harm presentations to general health settings actually reach specialist mental health follow-up appointments. Therefore, even if responses at that point are known to be effective they do not make a significant contribution to reducing repeat self-harm overall. We describe health system organisational change strategies to improve health service engagement for the target group, and present data demonstrating the effectiveness of these strategies.

Micromachining of a piezocomposite transducer using a copper vapor laser

A 1-3 piezocomposite transducer with front face dimensions of 2 x 2 mm has been micromachined using a copper vapor laser. The device consists of PZT5A piezoceramic pillars with a 65-micron pitch suspended in a low viscosity thermosetting polymer. The kerf width is 13 microns, and the transducer thickness is 170 microns, making the device suitable for ultrasonic reception at frequencies close to 10 MHz.

A germline deletion of p14(ARF) but not CDKN2A in a melanoma-neural system tumour syndrome family

The melanoma-astrocytoma syndrome is characterized by a dual predisposition to melanoma and neural system tumours, commonly astrocytoma. Germline deletions of the region on 9p21 containing the CDKN2A and CDKN2B genes and CDKN2A exon 1beta have been reported in kindreds, implicating contiguous tumour suppressor gene deletion as a cause of this syndrome. We describe a family characterized by multiple melanoma and neural cell tumours segregating with a germline deletion of the p14(ARF)-specific exon 1beta of the CDKN2A gene. This deletion does not affect the coding or minimal promoter sequences of either the CDKN2A or CDKN2B genes. Our results are consistent with either: (i) loss of p14(ARF) function being the critical abnormality associated with this syndrome, rather than contiguous loss of both the CDKN2A and CDKN2B genes as suggested previously; or (ii) disruption of expression of p16 by mechanisms as yet unknown.

Correlation between human immunodeficiency virus genotypic resistance and virologic response in patients receiving nelfinavir monotherapy or nelfinavir with lamivudine and zidovudine

The relationship between detectable human immunodeficiency virus (HIV) genotypic resistance and virologic response was compared in patients receiving nelfinavir as monotherapy (16 weeks) or in combination with lamuvidine and zidovudine (48 weeks). Two patient groups were defined on the basis of the presence or absence of substitutions associated with nelfinavir, a protease (PR) inhibitor, and/or a reverse transcriptase (RT) inhibitor. HIV RNA levels <50 copies/mL were achieved in 17 (85%) of 20 combination-therapy patients without genotypic resistance (PR-RT(-)) versus only 1 (17%) of 6 patients with genotypic resistance (PR-RT(+)). PR-RT(-) patients exhibited greater and more durable virus suppression compared with PR-RT(+) patients. All 6 PR-RT(+) patients had virus with M184V (lamuvidine resistance); 3 isolates also contained D30N (nelfinavir resistance). M184V preceded D30N in all determinable instances. In this study, suppression of HIV replication to <50 copies/mL was associated with durable response and reduced incidence of resistance. Results also indicate that combination regimens can fail despite the absence of detectable genotypic PR resistance.

Micro-ablation with high power pulsed copper vapor lasers

Visible and UV lasers with nanosecond pulse durations, diffraction-limited beam quality and high pulse repetition rates have demonstrated micro-ablation in a wide variety of materials with sub-micron precision and sub-micron-sized heat-affected zones. The copper vapour laser (CVL) is one of the important industrial lasers for micro-ablation applications. Manufacturing applications for the CVL include orifice drilling in fuel injection components and inkjet printers, micro-milling of micromoulds, via hole drilling in printed circuit boards and silicon machining. Recent advances in higher power (100W visible, 5W UV), diffraction-limited, compact CVLs are opening new possibilities for manufacturing with this class of nanosecond laser.

Genes for human arylamine N-acetyltransferases in relation to loss of the short arm of chromosome 8 in bladder cancer

Polymorphisms of N-acetyltransferase type 2 (NAT2) conferring the slow acetylator phenotype have been linked to increased susceptibility to arylamine-induced bladder cancer in Caucasians. Genes for NAT2, the other NAT isozyme, NAT1, and a NAT pseudogene (NATP) are found on 8p22, a region displaying loss of heterozygosity, particularly in invasive bladder tumours. A restriction enzyme digestion map has defined the relative positions of the NAT genes to each other and to adjacent CpG islands. NAT2, as a polymorphic gene of known function, is a potentially valuable marker for the detection of loss of heterozygosity in 8p22. Two approaches to investigate loss of heterozygosity at the NAT2 locus in bladder tumours have been used. (1) A cosmid containing NAT2 has been used in fluorescence in-situ hybridization on human exfoliated bladder cells collected from unselected bladder cancer outpatients. Loss of signal from the NAT2 cosmid was found in nine of the 20 patients. (2) A panel of 13 human bladder tumours was investigated for loss of heterozygosity using the polymorphism in the NAT2 gene as a marker. Loss of heterozygosity at the NAT2 locus has been compared with loss of heterozygosity at adjacent microsatellite marker sites known to be located on 8p. There is agreement between loss of heterozygosity at the NAT2 locus and adjacent microsatellite marker loci in 11 of the tumours but two of the tumours appear to show retention at the NAT2 locus. More extensive mapping of the region around the NAT loci, particularly on the centromeric side, is important to pinpoint possible tumour suppressor genes or their modifiers in the region. There are no other expressed sequences known in this region and therefore NAT genes are important genetic landmarks.

Genotypic and phenotypic characterization of human immunodeficiency virus type 1 variants isolated from patients treated with the protease inhibitor nelfinavir

Nelfinavir mesylate (formerly AG1343) is a potent and selective inhibitor of human immunodeficiency virus (HIV) protease approved for the treatment of individuals infected with HIV. Nucleotide sequence analysis of protease genes from plasma HIV type 1 (HIV-1) RNA revealed a unique aspartic acid (D)-to-asparagine (N) substitution at residue 30 (D30N) in 25 of 55 patients treated with nelfinavir for a median of 13 weeks. Although the appearance of D30N was occasionally associated with concurrent or sequential emergence of other changes (e.g., at residues 35, 36, 46, 71, 77, and 88), genotypic changes associated with phenotypic resistance to other protease inhibitors were not observed (e.g., at residues 48, 50, 82, and 84) or were only rarely observed (e.g., at residue 90). In phenotypic assays, viral isolates with high-level resistance to nelfinavir remained susceptible to indinavir, saquinavir, ritonavir, and amprenavir (formerly VX-478/141W94). Similar results were observed in phenotypic assays utilizing HIV-1 NL4-3, which contained the D30N substitution alone or in combination with substitutions at other residues (e.g., residues 46, 71, and 88). These data indicate that the initial pathway of resistance to nelfinavir is unique and suggest that individuals failing short courses of nelfinavir-containing regimens may respond to regimens containing other protease inhibitors.