How does Context Influence Implementation Mechanism of Publicly Funded Health Insurance Schemes in Indian States

Introduction:

The success of any insurance scheme is contingent upon well-defined processes related to payment, referral, grievances and quality control mechanisms. Any deviation observed may result in unsatisfactory performance. This study attempts to examine various processes related to the implementation of Pradhan Mantri Jan Arogya Yojana (PMJAY) and a state-specific insurance scheme across three states of India.

Objective:

To describe the policies and process adapted by selected states in implementing a government-sponsored health insurance scheme. To examine the strategies that work effectively, how they operate and what contextual factors enable or disable the desired implementation mechanisms.

Methodology:

The three states of Karnataka, Chhattisgarh, and Odisha were selected to understand various processes related to the implementation of Publicly Funded Health Insurance Schemes (PFHIS) schemes in diverse settings. A realist evaluation framework was used to study the contexts and mechanisms and how this influences outcomes.

Results:

The three schemes differ in implementation modes and follow different strategies owing to the local contexts. Some mechanisms worked well in specific contexts, whereas similar things have hindered the process in other contexts.

Conclusion:

The evidence generated is helpful to strengthen implementation processes under PMJAY and allows learning from each other to increase uptake of the scheme.

Determining the Role of Community Engagement in the Design of Primary Care Models Addressing Non-communicable Diseases

Non-communicable diseases (NCDs) are a major health concern in India and were estimated to account for 63% of all deaths in 2016, and if left unaddressed, they could cost India approximately US$3.55 trillion in economic losses by 2030. The National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases & Stroke (NPCDCS) has identified community engagement to enable behaviour change as a top intervention to manage various NCDs. Community engagement initiatives in India are plagued with multiple issues such as a lack of long-term focus, non-clarity on budgets, ineffective programme planning and the absence of visionary leadership and governance. This article attempts to understand the role of community engagement in providing access to NCD awareness and to support action on prevention, screening, diagnosis, treatment and compliance, so that the community is empowered to proactively behave in a way to prevent and manage NCDs effectively and hence reduce the incidence of NCDs. The article is based on research study using a mixed-method approach in a five-step manner, which included secondary and primary research. After scanning 200 initiatives across the spectrum of community engagement globally, 20 were shortlisted and detailed case studies of the initiatives were analysed and presented. In addition, primary research was pursued to propose recommendations for community engagement across the areas of visioning and planning, leadership and governance, and community involvement. Some guiding principles were recommended to create an environment of shared leadership and collaboration for community engagement, consequently creating greater positive influence on NCD management within the community.

Assessment of Workload of ASHAs: A Multi-stakeholder Perspective Study for Task-sharing and Task-shifting

The Accredited Social Health Activist (ASHA) programme has proven to be cost-effective and successful in addressing the growing shortage of health workers and reaching the vulnerable. ASHA’s contribution towards the improvement in maternal and child health and other health programmes at the community level is reported and acknowledged widely in literature. However, nearly 16 years into the introduction of ASHA, challenges in terms of workload, fatigue, poor work–life balance and low levels of compensation have emerged.

Aim:

To assess the workload on ASHAs, impact of their responsibilities on their quality of life and the potential for structured task sharing/shifting among other healthcare workers.

Methodology:

The study used a mixed-method approach with data and source triangulation. A multi-stage random sampling method was used to collect the data. Qualitative research was carried out to explore ASHAs’ and stakeholders’ perspectives, and a thematic analysis was undertaken using NVivo-12. ASHAs’ quality of life was also measured using the World Health Organization Quality of Life (WHO QOL)-BREF. The study was carried out in three districts of Karnataka: Mysuru, Raichur and Koppala.

Results:

The majority of ASHAs reported that they experience work burden in terms of population coverage, extended hours of work and additional tasks. Lack of access to transportation, inadequate support from other healthcare personnel and delayed payment of incentives add to them often feeling overworked and underpaid. The research also elicited perspectives on ASHAs’ work from different stakeholders. Findings from the study emphasise the necessity for sharing/shifting of selected tasks among other frontline health workers based on complexity and capabilities.

Effects of Various Financial and Non-financial Incentives on the Performance of Accredited Social Health Activist: Evidence from Two Selected Districts of Odisha

Introduction:

The performance of Accredited Social Health Activists (ASHAs) is crucial for the achievement of the ‘health for all’ goal in India. The performance and motivation of workforce are dependent on various financial and non-financial incentives. This study analyses the linkage of current incentive practices and perceived rewards/sanctions, with the motivation and performance of ASHA.

Methods:

Cross-sectional qualitative approach and interpretive structural modelling (ISM).

Results:

The motivation and performance of ASHAs were driven by various inter-related factors. The predominant rewarding factors identified were: monetary incentives, awards, and support and respect of the community towards the ASHAs. Dissatisfaction was fuelled by factors, such as sense of underpayment, comparison with peers and the community cadres of other departments, erratic duty hours, scarce disbursement of resources, financial insecurity post-retirement, difficulty in reading or writing, unavailability of health services and medicines in the nearby healthcare facilities.

Conclusions:

For a sustained advance in motivation and performance of ASHAs, the public health systems’ focus needs to be oriented on: capacity building; optimal resource allocation, rationalised payoffs to the ASHAs working in difficult terrains and improving availability of healthcare services in primary healthcare facilities.

Assessment of the Teaching on Alcohol Use and Management in Current Health Professional Curricula in India

Alcohol consumption is globally a serious public health challenge, and it is rampant across all parts of India. The COVID-19 pandemic has added to the overall burden of alcoholism due to long working hours, increased mental stress, depression, and so on. Primary care physicians have an important role in assessing risk and providing counselling, intervention and treatment of alcohol misuse. Studies have demonstrated primary health care facilities to be ideally suited for alcohol prevention and cessation interventions as most patients with alcohol use disorders (AUDs) seek treatment from facilities in the primary care setting in India. Thus, the training of healthcare professionals is vital in addressing AUDs in India. The Indian government is setting up Health and Wellness Centres across the country intended to address long-term care and holistic health promotion. At the same time, healthcare providers have expressed their limited competence in cessation and counselling practices related to AUDs. One of the attributing factors for these limitations is the paucity of exposure during the formative years. With this background, a review was undertaken of the current prescribed undergraduate professional curricula (medical, nursing, dentistry and physiotherapy) in India to assess its current status and preparedness in addressing alcohol misuse. The study findings emphasise the need to bolster the continuing education of health professionals aimed at health promotion and preventive strategies by hands-on training, brief workshops, supervised clinical experience by extramural faculty such as addiction psychiatrists, use of standardised patients, role play, and other similar methods.

Effectiveness of Supply Chain Planning in Ensuring Availability of CD/NCD Drugs in Non-Metropolitan and Rural Public Health System

Several studies have reported on the shortage of drugs with the changing demographic and disease profile, especially triggered by the growing burden of lifestyle diseases. However, very few have evaluated the demand-side challenges from the objective of universalisation of healthcare. Therefore, this study was designed to evaluate the factors that have impeded access to affordable generic and essential drugs in non-metropolitan urban and rural India. The study was conducted in six states and responses were elicited from a sample of doctors, pharmacists, nurses, accredited social health activist (ASHA) workers, state officials, warehouse managers and patients across the study states. The study reveals that while the acceptance of prescribing generic drugs has improved over the last decade, the use of branded drugs has been restricted only to complex cases or where generic drug efficacy has not been established. The centralised procurement efficiencies seem to have hit a plateau in terms of assuring drug availability to the last mile, thereby impacting local purchase, especially pandemic procurement. Most states have also established dedicated corporations for drug procurement, albeit at different levels of organisational maturity as far as adherence to the processes and systems are concerned. However, supply chain phenomena like the bullwhip effect gets accentuated given the levels of our public health system. Learnings from other consumer-facing sectors with similar challenges of increased variability and uncertainty are yet to be explored for the health sector to leapfrog towards achieving improved ‘drug availability’ or ‘zero stock-out’. Standardising drug categories, regular updating of the essential drug list (EDL) reflecting the demographic and disease profile, various practices like complete digitisation, rolling forecasts, stock-keeping unit rationalisation, flexible public procurement contracts, etc., have been explored as potential solutions in this paper. Creating a dedicated team of forecasters within the procurement organisations, well adept at using analytics, could be key to real-time demand estimation, paving the way for a quarterly rolling forecast to facilitate procurement using well-designed rate contracts with suppliers that captures variability in such rolling forecasts.

Innovations in Primary Healthcare: A Review of Initiatives to Promote Maternal Health in Tamil Nadu

One of the key factors that has helped the state of Tamil Nadu to make significant progress in the health sector, especially in maternal health, is an enabling political environment in the state that has prioritised programmes for the welfare of women and children, irrespective of the party in power. This article reviews 10 key innovations in maternal health and tribal health introduced in the state of Tamil Nadu from 2005–2006 to 2020–2021. The specific questions addressed are as follows: what are the special innovative schemes introduced by the state of Tamil Nadu to promote maternal health? Whether and to what extent utilisation of public delivery system for maternal services has increased over the past 15 years or so?

The overall impact of these initiatives on the maternal health of the state is assessed by analysing two indicators: trends in maternal mortality ratio (MMR) and financial burden due to delivery in public and private facilities. MMR in the state of Tamil Nadu is steadily falling—from 111 in 2004–2006 to 60 in 2016–2018. While average out-of-pocket expenditure (OOPE) during delivery in the public sector has increased from ₹2,454 in 2014 to ₹3,465 in 2017–2018, in the private sector, it has increased from ₹32,182 in 2014 to ₹34,635 in 2017–2018. OOPE in private facilities is nearly ten times higher than OOPE in public facilities, in both rural and urban areas. While the overall status of maternal health has improved significantly in the state, there are wide variations within and across districts. However, significant improvements in the overall health status can be achieved only if such inequities are reduced systematically, and efforts are being made to reduce such inequities.

Mapping Healthcare Data Sources in India

Healthcare data sources collect and report various kinds of health data related to routine service delivery, patient-based care, resources related to infrastructure, human resources and finance. Typically, in developing countries, multiple sources are used for the provision of healthcare data, and these include national health surveys, census and civil registration systems, and routine reporting systems. In addition, rapid infusion of information technology has increased adoption of management information systems in public health programs. During the last decade, India has witnessed a sharp rise in the number of healthcare data sources as identified in this review. These sources have increased data availability in multiple data deficient areas. However, the careful appraisal indicates data gaps in numerous important areas. These sources also suffer from inherent quality, coverage and standardisation issues. To overcome these challenges, remedial measures include the development of a national healthcare data plan, a survey calendar, designation of a nodal survey agency, adoption of indicator dictionary, adequate capacity building, and increased coordination among stakeholders.

Role of the private sector in vaccination service delivery in India: evidence from private-sector vaccine sales data, 2009-12

BACKGROUND

India's Universal Immunization Programme (UIP) provides basic vaccines free-of-cost in the public sector, yet national vaccination coverage is poor. The Government of India has urged an expanded role for the private sector to help achieve universal immunization coverage. We conducted a state-by-state analysis of the role of the private sector in vaccinating Indian children against each of the six primary childhood diseases covered under India's UIP.

METHODS

We analyzed IMS Health data on Indian private-sector vaccine sales, 2011 Indian Census data and national household surveys (DHS/NFHS 2005-06 and UNICEF CES 2009) to estimate the percentage of vaccinated children among the 2009-12 birth cohort who received a given vaccine in the private sector in 16 Indian states. We also analyzed the estimated private-sector vaccine shares as function of state-specific socio-economic status.

RESULTS

Overall in 16 states, the private sector contributed 4.7% towards tuberculosis (Bacillus Calmette-Guérin (BCG)), 3.5% towards measles, 2.3% towards diphtheria-pertussis-tetanus (DPT3) and 7.6% towards polio (OPV3) overall (both public and private sectors) vaccination coverage. Certain low income states (Uttar Pradesh, Rajasthan, Madhya Pradesh, Orissa, Assam and Bihar) have low private as well as public sector vaccination coverage. The private sector's role has been limited primarily to the high income states as opposed to these low income states where the majority of Indian children live. Urban areas with good access to the private sector and the ability to pay increases the Indian population's willingness to access private-sector vaccination services.

CONCLUSION

In India, the public sector offers vaccination services to the majority of the population but the private sector should not be neglected as it could potentially improve overall vaccination coverage. The government could train and incentivize a wider range of private-sector health professionals to help deliver the vaccines, especially in the low income states with the largest birth cohorts. We recommend future studies to identify strengths and limitations of the public and private health sectors in each Indian state.

Implications of private sector Hib vaccine coverage for the introduction of public sector Hib-containing pentavalent vaccine in India: evidence from retrospective time series data

OBJECTIVE

Haemophilus influenzae type b (Hib) vaccine has been available in India's private sector market since 1997. It was not until 14 December 2011 that the Government of India initiated the phased public sector introduction of a Hib (and DPT, diphtheria, pertussis, tetanus)-containing pentavalent vaccine. Our objective was to investigate the state-specific coverage and behaviour of Hib vaccine in India when it was available only in the private sector market but not in the public sector. This baseline information can act as a guide to determine how much coverage the public sector rollout of pentavalent vaccine (scheduled April 2015) will need to bear in order to achieve complete coverage.

SETTING

16 of 29 states in India, 2009-2012.

DESIGN

Retrospective descriptive secondary data analysis.

DATA

(1) Annual sales of Hib vaccines, by volume, from private sector hospitals and retail pharmacies collected by IMS Health and (2) national household surveys.

OUTCOME MEASURES

State-specific Hib vaccine coverage (%) and its associations with state-specific socioeconomic status.

RESULTS

The overall private sector Hib vaccine coverage among the 2009-2012 birth cohort was low (4%) and varied widely among the studied Indian states (minimum 0.3%; maximum 4.6%). We found that private sector Hib vaccine coverage depends on urban areas with good access to the private sector, parent's purchasing capacity and private paediatricians' prescribing practices. Per capita gross domestic product is a key explanatory variable. The annual Hib vaccine uptake and the 2009-2012 coverage levels were several times higher in the capital/metropolitan cities than the rest of the state, suggesting inequity in access to Hib vaccine delivered by the private sector.

CONCLUSIONS

If India has to achieve high and equitable Hib vaccine coverage levels, nationwide public sector introduction of the pentavalent vaccine is needed. However, the role of private sector in universal Hib vaccine coverage is undefined as yet but it should not be neglected as a useful complement to public sector services.

A cross-sectional survey of the models in Bihar and Tamil Nadu, India for pooled procurement of medicines

BACKGROUND

In India, access to medicine in the public sector is significantly affected by the efficiency of the drug procurement system and allied processes and policies. This study was conducted in two socioeconomically different states: Bihar and Tamil Nadu. Both have a pooled procurement system for drugs but follow different models. In Bihar, the volumes of medicines required are pooled at the state level and rate contracted (an open tender process invites bidders to quote for the lowest rate for the list of medicines), while actual invoicing and payment are done at district level. In Tamil Nadu, medicine quantities are also pooled at state level but payments are also processed at state level upon receipt of laboratory quality-assurance reports on the medicines.

METHODS

In this cross-sectional survey, a range of financial and non-financial data related to procurement and distribution of medicine, such as budget documents, annual reports, tender documents, details of orders issued, passbook details and policy and guidelines for procurement were analysed. In addition, a so-called ABC analysis of the procurement data was done to to identify high-value medicines.

RESULTS

It was observed that Tamil Nadu had suppliers for 100% of the drugs on their procurement list at the end of the procurement processes in 2006, 2007 and 2008, whereas Bihar's procurement agency was only able to get suppliers for 56%, 59% and 38% of drugs during the same period. Further, it was observed that Bihar's system was fuelling irrational procurement; for example, fluconazole (antifungal) alone was consuming 23.4% of the state's drug budget and was being procured by around 34% of the districts during 2008-2009. Also, the ratios of procurement prices for Bihar compared with Tamil Nadu were in the range of 1.01 to 22.50. For 50% of the analysed drugs, the price ratio was more than 2, that is, Bihar's procurement system was procuring the same medicines at more than twice the prices paid by Tamil Nadu.

CONCLUSION

Centralized, automated pooled procurement models like that of Tamil Nadu are key to achieving the best procurement prices and highest possible access to medicines.

Association between household air pollution sand neonatal mortality: an analysis of Annual Health Survey results, India

BACKGROUND

In India, household air pollution (HAP) is one of the leading risk factors contributing to the national burden of disease. Estimates indicate that 7.6% of all deaths in children aged under 5 years in the country can be attributed to HAP. This analysis attempts to establish the association between HAP and neonatal mortality rate (NMR).

METHODS

Secondary data from the Annual Health Survey, conducted in 284 districts of nine large states covering 1 404 337 live births, were analysed. The survey was carried out from July 2010 to March 2011 (reference period: January 2007 to December 2009). The primary outcome was NMR. The key exposure was the use of firewood/crop residues/cow dung as fuel. The covariates were: sociodemographic factors (place of residence, literacy status of mothers, proportion of women aged less than 18 years who were married, wealth index); health-system factors (three or more antenatal care visits made during pregnancy; institutional deliveries; proportion of neonates with a stay in the institution for less than 24 h; percentage of neonates who received a check-up within 24 h of birth); and behavioural factors (initiation of breast feeding within 1 h). Descriptive analysis, with district as the unit of analysis, was performed for rural and urban areas. Bivariate and multivariable linear regression analysis was carried out to investigate the association between HAP and NMR.

RESULTS

The mean rural NMR was 42.4/1000 live births (standard deviation [SD] = 11.4/1000) and urban NMR was 33.1/1000 live births (SD=12.6/1000). The proportion of households with HAP was 92.2% in rural areas, compared to 40.8% in urban areas, and the difference was statistically significant (P < 0.001). HAP was found to be strongly associated with NMR after adjustment (β = 0.22; 95% confidence interval [CI] = 0.09 to 0.35) for urban and rural areas combined. For rural areas separately, the association was significant (β = 0.30; 95% CI = 0.13 to 0.45) after adjustment. In univariable analysis, the analysis showed a significant association in urban areas (β = 0.23; 95% CI = 0.12 to 2.34) but failed to demonstrate an association in multivariable analysis (β = 0.001; 95% CI = -0.15 to 0.15).

CONCLUSION

Secondary data from district level indicate that HAP is associated with NMR in rural areas, but not in urban areas in India.

Pediatricians' perspectives on pneumococcal conjugate vaccines: An exploratory study in the private sector

There is a lack of information on supply-side determinants, their utilization, and the access to pneumococcal vaccination in India. The objective of this exploratory study was to document the perceptions and perspectives of practicing pediatricians with regard to pneumococcal conjugate vaccines (PCVs) in selected metropolitan areas of India. A qualitative study was conducted to generate evidence on the perspective of pediatricians practicing in the private sector regarding pneumococcal vaccination. The pediatricians were identified from 11 metropolitan areas on the basis of PCV vaccine sales in India through multilevel stratified sampling method. Relevant information was collected through in-depth personal interviews. Finally, qualitative data analysis was carried out through standard techniques such as the identification of key domains, words, phrases, and concepts from the respondents. We observed that the majority (67.7%) of the pediatricians recommended pneumococcal vaccination to their clients, whereas 32.2% recommended it to only those who could afford it. More than half (62.9%) of the pediatricians had no preference for any brand and recommended both a 10-valent pneumococcal conjugate vaccine (PCV10) and a 13-valent PCV (PCV13), whereas 8.0% recommended none. An overwhelming majority (97.3%) of the pediatricians reported that the main reason for a patient not following the pediatrician's advice for pneumococcal vaccination was the price of PCV. To reduce childhood pneumonia-related burden and mortality, pediatricians should use every opportunity to increase awareness about vaccine-preventable diseases, especially vaccine-preventable childhood pneumonia among their patients.

Health technology assessment in India: the potential for improved healthcare decision-making

Health technology assessment (HTA) is a multidisciplinary approach that uses clinical effectiveness, cost-effectiveness, policy and ethical perspectives to provide evidence upon which rational decisions on the use of health technologies can be made. It can be used for a single stand-alone technology (e.g. a drug, a device), complex interventions (e.g. a rehabilitation service) and can also be applied to individual patient care and to public health. It is a tool for enabling the assessment and comparison of health technologies using the same metric of cost-effectiveness. This process benefits the patient, the health service, the healthcare payer and the technology producer as only technologies that are considered cost-effective are promoted for widespread use. This leads to greater use of effective technologies and greater health gain. The decision-making process in healthcare in India is complex owing to multiplicity of organizations with overlapping mandates. Often the decision-making is not evidence-based and there is no mechanism of bridging the gap between evidence and policy. Elsewhere, HTA is a frequently used tool in informing policy decisions in both resource-rich and resource-poor countries. Despite national organizations producing large volumes of research and clinical guidelines, India has not yet introduced a formal HTA programme. The incremental growth in healthcare products, services, innovation in affordable medical devices and a move towards universal healthcare, needs to be underpinned with an evidencebase which focuses on effectiveness, safety, affordability and acceptability to maximize the benefits that can be gained with a limited healthcare budget. Establishing HTA as a formal process in India, independent of healthcare providers, funders and technology producers, together with a framework for linking HTA to policy-making, would help ensure that the population gets better access to appropriate healthcare in the future.

Understanding public drug procurement in India: a comparative qualitative study of five Indian states

OBJECTIVE

To perform an initial qualitative comparison of the different procurement models in India to frame questions for future research in this area; to capture the finer differences between the state models through 53 process and price parameters to determine their functional efficiencies.

DESIGN

Qualitative analysis is performed for the study. Five states: Tamil Nadu, Kerala, Odisha, Punjab and Maharashtra were chosen to ensure heterogeneity in a number of factors such as procurement type (centralised, decentralised or mixed); autonomy of the procurement organisation; state of public health infrastructure; geography and availability of data through Right to Information Act (RTI). Data on procurement processes were collected through key informant analysis by way of semistructured interviews with leadership teams of procuring organisations. These process data were validated through interviews with field staff (stakeholders of district hospitals, taluk hospitals, community health centres and primary health centres) in each state. A total of 30 actors were interviewed in all five states. The data collected are analysed against 52 process and price parameters to determine the functional efficiency of the model.

RESULTS

The analysis indicated that autonomous procurement organisations were more efficient in relation to payments to suppliers, had relatively lower drug procurement prices and managed their inventory more scientifically.

CONCLUSIONS

The authors highlight critical success factors that significantly influence the outcome of any procurement model. In a way, this study raises more questions and seeks the need for further research in this arena to aid policy makers.

The use of single-fraction radiation therapy in cutaneous T-cell lymphoma

e19505

Background: Primary cutaneous lymphomas occur in 0.5 to 1 per 100,000 people every year in developed countries. Less than 1,000 cases of Mycosis Fungoides are diagnosed each year in the United States, with approximately 3 cases per 1,000,000 per year. Cutaneous T-cell lymphomas are responsive to radiation therapy, and local radiation therapy, total skin electron beam therapy, phototherapy (with UVB or PUVA), chemotherapy agents (nitrogen mustards, BCNU), retinoids, and steroids have all been used with varying degrees of success. Methods: This is a retrospective review of all cases of histology-proven cutaneous T-cell lymphoma treated with single-fraction radiation therapy at Northwestern Memorial Hospital in the Department of Radiation Oncology since 1990. We looked at response to treatment and local control. We reviewed the charts of 67 patients with cutaneous T-cell lymphoma, of which 40 patients and a total of 130 sites of disease received single-fraction radiation therapy and had available follow-up data. Results: Of the 130 lesions receiving a single-fraction of radiation, 86 (66%) received 800cGy in 1 fraction and 38 (29%) received 700cGy. 4 patients (3%) received 750cGy, 1 (<1%) received 550cGy and 1 (<1%) received 500cGy. Patients were treated with electron energies ranging from 6–18 MeV or photon energies ranging from 4–10 MV. Out of 130 lesions, 119 (92%) achieved a complete response (CR) to single-fraction radiation and 11 (8%) achieved a partial response (PR). There were 2 sites of relapse out of 130 treated sites, involving 2 patients. The median follow-up time was 4 months, mean follow-up time was 14 months, and 44% of patients had greater than 6 months of follow-up. Conclusions: This review of the experience at our institution since 1990 shows single-fraction radiation therapy to be an effective treatment for cutaneous T-cell lymphoma, with high response rates and very low relapse rates.

No significant financial relationships to disclose.

The ultrastructural architecture of the tissue/hard-tissue replacement interface

This investigation examined the tissue response and interfacial bonding between bone and hard-tissue replacement (HTR) using scanning (SEM) and transmission (TEM) electron microscopy. Twenty adult male Sprague-Dawley rats were anesthetized and a hole (1.0 mm deep by 2.0 mm wide) was drilled in the calvarium. Subsequently, HTR was implanted and the wound closed. The implants and surrounding tissues were removed at 7, 14, 28, and 56 days and prepared for examination by SEM or TEM. Scanning electron microscopic analysis revealed a typical inflammatory response that subsided by day 14. At that time, a fine layer of collagen fibrils (fibrous envelope) was observed covering the polymeric surface. Energy dispersive x-ray analysis (EDXA) showed no sign of mineralization. Ultrastructural analysis demonstrated that the fibrous envelope was bilaminar; it consisted of a relatively undifferentiated cellular layer adjacent to the polymer and an outer fibrous region. Scanning electron microscopic analysis of 28-day implants showed that osteoblasts had migrated onto the outer surface of the fibrous envelope and that calcification had been initiated as judged by EDXA. Electron microscopic examination confirmed previous observations of an undifferentiated cellular layer along the interfacial boundary, but also showed both macrophages and foreign-body giant cells. At 56 days, bone was observed to contact and cover the fibrous envelope surrounding the polymeric bead; however, EDXA showed that the fibrous envelope remained noncalcified. Transmission electron microscopic analysis revealed that the inner cellular layer was beginning to mature, as indicated by the presence of numerous cellular organelles. This maturation was accompanied by an increased incidence of macrophages as well as foreign-body giant cells. Within the time constraints of the experimental design, it is apparent that a bilaminar layer of cells and fibers remains between the HTR and the bone. Additional studies will be necessary, over extended time periods, to determine whether the bilaminar layer remains a constant feature between the HTR and the surrounding bone or whether this region is gradually supplanted by the ingrowing bone.