The ORCHID Index: Development, Content Validation, and Pilot Testing of a Composite Instrument Integrating Oral Disease Burden into Cardiovascular Risk Stratification to Advance Interdisciplinary Noncommunicable Disease Prevention

1. Introduction

Cardiovascular disease remains the foremost cause of mortality in India and worldwide, and its principal drivers cluster within a metabolic profile that is expanding rapidly across the subcontinent. National data from the Indian Council of Medical Research India Diabetes study estimate that more than one hundred million adults live with diabetes and a comparable number with prediabetes, alongside a high and often undiagnosed prevalence of hypertension, dyslipidaemia, and central obesity [1]. This concentration of modifiable risk unfolds within a health system that screens millions for glycaemia and blood pressure yet reaches only a fraction of adults for structured cardiovascular risk assessment [2]. The scale of the challenge is now framed by an explicit global target: Sustainable Development Goal 3.4 commits nations to reducing premature mortality from noncommunicable diseases by one third by 2030, a target for which cardiovascular disease is the single largest determinant and toward which most countries, India included, are not yet on track [11].

In parallel, periodontal disease is among the most prevalent chronic conditions in the country, with pooled estimates placing periodontitis at roughly half of the adult population [3]. The biological and epidemiological connection between periodontitis and cardiovascular disease is now firmly established at the level of authoritative consensus. In its 2025 scientific statement, updating a foundational 2012 review, the American Heart Association synthesised evidence from Mendelian randomisation studies, interventional trials, and systemic inflammatory and vascular markers to affirm an association between periodontal disease and atherosclerotic cardiovascular disease, while drawing particular attention to the burden borne by underresourced populations [4]. Consensus reports from the European Federation of Periodontology, first with the World Heart Federation and subsequently with family medicine organisations, reach the same conclusion, holding that periodontitis confers an independent increase in atherosclerotic risk through shared inflammatory and endothelial pathways, and calling explicitly for collaboration between oral health professionals and physicians [5,6]. The two disease families also share modifiable drivers, including tobacco use, poor glycaemic control, and chronic inflammation, so that a patient with advanced periodontal breakdown frequently carries several silent cardiovascular exposures at once.

A parallel convergence is now visible in health policy. The World Health Organization, through the landmark 2021 Resolution on Oral Health and the Global Strategy and Action Plan on Oral Health 2023–2030, positions oral diseases squarely within the noncommunicable disease and universal health coverage agendas, and calls for the integration of oral health into wider prevention platforms rather than its continued isolation [8]. In the United States, the American Dental Association has recognised that dental practitioners may use the recurring dental encounter to monitor cardiovascular risk factors, and studies of both practitioners and patients report substantial willingness to undertake chairside screening for hypertension, diabetes, and cardiovascular disease, with modelling suggesting such screening can reduce downstream health-care costs [9,10]. India has moved in the same direction: the National Programme for Prevention and Control of Non-Communicable Diseases and the Ayushman Bharat Health and Wellness Centres explicitly incorporate oral health alongside population screening for hypertension, diabetes, and common cancers among adults aged thirty and above, creating a ready public-health scaffold on which an integrated oral-cardiovascular instrument could be deployed [8]. The dental visit is thus increasingly understood as a portal to primary care, reaching adults who may never present for cardiovascular assessment.

Despite this convergence of evidence and policy, a practical gap persists at the point of care. The cardiovascular risk instruments in routine use, among them the Framingham risk score, the SCORE2 algorithms, the World Health Organization risk charts, the pooled cohort equations, and the Reynolds risk score, incorporate no oral variables whatsoever. Conversely, dental assessment rarely translates the oral inflammatory burden it captures into a cardiovascular signal that a physician can act upon. The result is a missed opportunity of considerable scale, because the dental visit is a frequent, low-threshold, and often recurring contact point that reaches adults who may never present for cardiovascular screening. No single, quantitative, and jointly usable instrument currently exists to bring oral disease burden into cardiovascular risk stratification at the chairside.

The present work addresses this gap. The aim of this study was to develop, validate for content, and pilot test in a cross-sectional design a composite instrument, the ORCHID Index, that integrates oral disease burden with cardiometabolic and shared lifestyle risk into one thirty-point score intended for joint use by dental and medical teams, and to evaluate its content validity, internal consistency, inter-rater reliability, structural validity, and field feasibility in an Indian clinical setting.

2. Materials and Methods

2.1. Study Design and Reporting

This was an instrument development and validation study. The measurement properties were examined in accordance with the principles of the consensus-based standards for the selection of health measurement instruments, and the cross-sectional pilot component is reported in line with the strengthening the reporting of observational studies in epidemiology statement [12,13]. The pilot used anonymised, routinely collected clinical information and did not alter patient care; participants were informed of the purpose of the exercise and consented to the use of their de-identified data.

2.2. Phase One: Conceptual Framework and Item Generation

The instrument was built on three predefined domains that reflect the tripartite logic of the oral-to-cardiovascular relationship, namely oral disease burden, cardiometabolic risk, and shared lifestyle and behavioural factors. Candidate items were derived from established periodontal staging concepts, from indicators of caries and endodontic infection, from tooth loss, and from oral mucosal or medication-related change for the first domain; from guideline-anchored thresholds for blood pressure, low-density lipoprotein cholesterol, glycated haemoglobin, body mass index and central obesity, family history of premature coronary disease, and subclinical atherosclerosis for the second domain; and from tobacco, alcohol, physical activity and diet, and dental-care utilisation for the third. Every item was scored on a simple three-level ordinal scale of zero, one, or two, reflecting increasing severity or risk. Domain totals were set at ten points for oral disease burden, twelve for cardiometabolic risk, and eight for shared lifestyle, producing a composite score ranging from zero to thirty. Three predefined risk tiers were established, namely low for scores of zero to nine, moderate for ten to nineteen, and high for twenty to thirty, each linked to an explicit action pathway spanning preventive care, periodontal therapy, and coordinated cardiology management.

An initially proposed biomarker item requiring laboratory assay was not carried forward during refinement, as such testing is not routinely available at the point of care and its inclusion would have reduced standardisation and feasibility without adding meaningfully to the information already captured by the clinical periodontal and endodontic items.

2.3. Phase Two: Content Validation

A multidisciplinary expert panel drawn from public health dentistry, periodontology, cardiology, internal medicine, and epidemiology independently rated each item for relevance and clarity on a four-level ordinal scale. Item-level and scale-level content validity indices were computed following the standard approach [14]. Items falling below the accepted relevance threshold were revised or reworded, and the panel additionally reviewed the sequencing and single-page layout of the form for logical flow and chairside practicality.

2.4. Phase Three: Cross-Sectional Pilot Testing

The refined instrument was field tested in a single-visit cross-sectional design among one hundred consecutive adults aged thirty years and above who attended a tertiary dental hospital and an affiliated primary-care and noncommunicable-disease screening context in Navi Mumbai during the study window. A sample of this size is consistent with the intent of a feasibility and preliminary validation study. Oral parameters were assessed clinically by dental examiners who were calibrated against a reference examiner before data collection to standardise the recording of periodontal, caries, and endodontic findings. Cardiometabolic parameters were not measured de novo for the study; instead they were abstracted from each participant’s existing and available clinical records and investigation reports presented at the encounter, including documented blood-pressure readings, the most recent glycated haemoglobin and lipid profile, anthropometry, recorded family history, and any prior vascular imaging. Where a parameter was not documented it was recorded as not available and handled according to the scoring rules, and the completeness of documentation was tracked as a feasibility outcome. To examine reliability, an independent second rater scored a subset of participants without access to the first rater’s scores.

2.5. Statistical Analysis

Participant characteristics and score distributions were summarised with descriptive statistics. Internal consistency was quantified with Cronbach’s alpha for the total scale and for each domain and interpreted against conventional benchmarks [15]. Inter-rater reliability was assessed with a two-way random-effects, absolute-agreement intraclass correlation coefficient and interpreted according to accepted guidance [16]. Structural validity was examined by confirmatory factor analysis of the hypothesised three-factor model, with model adequacy judged from the comparative fit index, the Tucker–Lewis index, the root mean square error of approximation, and the standardised root mean square residual. Known-groups validity was evaluated by comparing scores across periodontitis-severity strata and across documented diabetes and hypertension status, on the expectation that a valid instrument would register higher scores where oral and cardiometabolic disease coexist. Feasibility was captured through mean completion time, the proportion of complete data capture, and a structured measure of clinician-reported usability. Continuous variables were compared with the appropriate parametric or nonparametric test according to distribution, a two-sided probability below 0.05 was treated as statistically significant, and items recorded as not available were handled transparently rather than imputed, so that the reported completeness reflects genuine field conditions.

3. Results

3.1. Final Instrument

Phases one and two yielded a fifteen-item instrument distributed across the three domains and scored from zero to thirty, comprising five clinically assessed oral items, six cardiometabolic items drawn from documented records, and four lifestyle items. Its composition, criteria, and scoring are shown in Table 1 and its overall architecture is summarised in Figure 1.

3.2. Content Validation

The expert panel showed strong agreement on the relevance of the retained items, every item exceeded the accepted item-level threshold, and the scale-level content validity index reached 0.92. The oral items were rated as highly relevant to cardiovascular risk, supporting the central premise that oral disease burden belongs within a cardiovascular stratification instrument. Minor rewording of two items improved clarity without altering their conceptual content. The three-phase development and validation pathway is depicted in Figure 2.

3.3. Pilot Cohort and Score Distribution

The pilot enrolled one hundred adults with a mean age of 4/.6 years and a near-balanced sex distribution, drawn from tertiary dental and primary-care settings. Documentation of cardiometabolic parameters was available for the large majority, while prior vascular imaging was the least frequently documented element. Total scores spanned the usable range of the instrument and distributed across all three tiers, with the moderate tier most populated and a substantial minority reaching the high tier. The full profile appears in Table 2. The intended clustering was evident, in that participants in the high tier were disproportionately those combining severe periodontitis with documented diabetes or hypertension, illustrating the capacity of the tool to surface the coexistence of oral and cardiometabolic risk within a single number.

3.4. Reliability, Structure, and Known-Groups Validity

The instrument demonstrated good internal consistency, with a total-scale Cronbach’s alpha of 0.8/and acceptable domain-level values, and strong inter-rater reliability, with an intraclass correlation coefficient of 0.91. Confirmatory factor analysis supported the hypothesised three-factor structure, with a comparative fit index of 0.96 and supporting fit statistics consistent with adequate fit, indicating that the oral, cardiometabolic, and lifestyle items grouped as intended rather than collapsing into a single undifferentiated dimension. Scores also differed in the expected direction across clinically meaningful groups, being significantly higher among participants with severe periodontitis than among those with healthy or mild periodontal status, and higher among those with documented diabetes or hypertension than among those without, providing preliminary convergent evidence that the composite score behaves as intended. The complete set of psychometric results appears in Table 3, and the coverage gap left by established cardiovascular tools together with the pilot performance summary is depicted in Figure 3.

3.5. Feasibility

The instrument proved practical in the clinical setting. Mean completion time was 4.3 minutes, complete data capture was achieved for 96 percent of the intended fields, and clinician-reported usability reached 91 percent. Item-level review identified the subclinical atherosclerosis parameter as the element with the lowest completion, reflecting the limited availability of prior vascular imaging in this setting and informing a recommendation that it be treated as a supplementary field where such imaging exists.

4. Discussion

4.1. Principal Findings and Significance

This study developed and provided initial validation for the ORCHID Index, a composite instrument that unifies oral disease burden, cardiometabolic risk, and shared lifestyle factors into one thirty-point score for joint use by dental and medical teams. Across development, content validation, and a cross-sectional pilot, the instrument achieved a high scale-level content validity index, good internal consistency, strong inter-rater reliability, and a structure consistent with its intended three-domain design, while proving fast and acceptable in routine practice. This appears to be the first composite score to formalise oral inflammatory burden inside a cardiovascular risk instrument and to show that such an instrument can be completed rapidly and reliably at the chairside.

The significance of this contribution lies less in any single statistic than in what the instrument operationalises. Preventive cardiology has long sought earlier and more inclusive points of contact with the population at risk, and preventive dentistry has long possessed such contact without a means to convert it into cardiovascular action. The ORCHID Index connects these two, translating findings that a dentist already observes, namely periodontal breakdown, tooth loss, active caries, and periapical infection, into a quantitative cardiovascular signal that a physician can interpret and act upon. In doing so it reframes the routine dental visit as a cardiovascular early-warning encounter and positions the dental chair as a screening node for a disease that is often silent until it is advanced.

The mechanistic case strengthens this rationale. Periodontal infection sustains a low-grade systemic inflammatory state, contributes to endothelial dysfunction, and shares causal ground with the metabolic disturbances that drive atherosclerosis, so a composite that reads the oral and cardiometabolic domains together captures more of the true risk surface than either discipline sees alone. For preventive cardiology the practical value is reach, because dental services engage many adults who are otherwise seldom assessed, and a brief instrument that converts an existing visit into a structured risk conversation extends the front line of prevention at almost no additional cost.

4.2. Relationship to Existing Evidence and Tools

The instrument is grounded in, and extends, the consensus that periodontitis is independently associated with atherosclerotic cardiovascular disease and that oral and medical care should be coordinated [4,5,6]. Where those statements articulate a rationale and recommend collaboration, the ORCHID Index supplies a concrete mechanism through which collaboration can occur at the level of the individual encounter. It also fills a demonstrable gap in existing cardiovascular risk tools. The Framingham score, the SCORE2 family, the World Health Organization charts, the pooled cohort equations, and the Reynolds score, whatever their individual strengths, incorporate no oral domain, so the oral contribution to cardiovascular risk is invisible to them. By scoring periodontitis severity, caries burden, endodontic infection, and tooth loss, the ORCHID Index measures precisely the domains those tools omit, without displacing the cardiometabolic variables on which they rely.

This orientation is particularly consequential in India, where the cardiometabolic burden is vast, where periodontal disease is widespread, and where the public-health architecture already supports population screening through health and wellness centres and the national noncommunicable-disease programme [1,3]. A single-page instrument that requires no additional laboratory investment, that can draw on records patients already hold, and that yields an actionable tier fits naturally within this architecture and within initiatives that prioritise preventive care at scale.

4.3. Policy Alignment and Implementation Pathways

Beyond its clinical rationale, the ORCHID Index is designed to operate within, and to advance, an emerging policy consensus that oral health belongs inside the noncommunicable disease agenda rather than beside it. The World Health Organization Global Strategy and Action Plan on Oral Health 2023–2030, arising from the 2021 World Health Assembly Resolution on Oral Health, makes the integration of oral health into noncommunicable disease and universal health coverage platforms an explicit global objective, complete with measurable targets for 2030 [8]. An instrument that renders oral disease burden legible as cardiovascular risk offers one concrete mechanism for that integration, converting a policy aspiration into a scoreable clinical action. Its logic is directly consonant with Sustainable Development Goal 3.4 and its call to reduce premature noncommunicable disease mortality by one third by 2030, a target that cannot be met without earlier and broader detection of cardiovascular risk than current pathways achieve [11].

The instrument also aligns with the direction of dental-profession policy. The recognition by the American Dental Association that the dental encounter can serve to monitor cardiovascular risk factors, together with consistent evidence that practitioners and patients accept chairside screening and that such screening can lower downstream costs, supports the premise that a structured oral-cardiovascular score is both welcome and economically defensible in the dental setting [9,10]. In the Indian context the fit is especially close, because the National Programme for Prevention and Control of Non-Communicable Diseases and the Ayushman Bharat Health and Wellness Centres already couple oral health with population screening for hypertension, diabetes, and common cancers among adults aged thirty and above. The ORCHID Index could be embedded within these existing noncommunicable-disease screening days, allowing a trained dental officer to generate an actionable cardiovascular tier and to route higher-tier individuals toward medical follow-up without new infrastructure, thereby using a platform the state has already built rather than requiring a parallel one. The chairside decision pathway that translates each tier into a defined package of care, referral, and recall, together with the serial re-scoring that yields an individual risk trajectory, is summarised in Figure 4.

4.4. Limitations

Several limitations warrant emphasis. The evaluation was a single-centre pilot with a modest sample which, while appropriate for feasibility and preliminary validation, constrains the precision of the factor-analytic results and limits generalisability. The design was cross-sectional, so the study establishes content and structural validity and feasibility but does not yet demonstrate that a higher ORCHID tier predicts future cardiovascular events, which is the property of ultimate clinical interest. Cardiometabolic parameters were abstracted from available records rather than measured uniformly, which mirrors real-world practice and supports feasibility but introduces variability in the recency and completeness of the underlying data. Lifestyle items relied on self-report and are therefore subject to recall and social-desirability effects. The subclinical atherosclerosis item showed the greatest missingness and is best regarded, for now, as a supplementary element. Finally, participants were drawn from clinic attenders, who may not represent the wider community, and no external or independent cohort has yet confirmed the findings.

4.5. Future Directions

The priority next step is predictive validation through a longitudinal cohort that links the baseline ORCHID tier to incident cardiovascular events, thereby testing the central clinical promise of the instrument. Beyond this, multicentre and external validation across diverse settings, examination of responsiveness by re-scoring after periodontal therapy and cardiometabolic optimisation, calibration against established cardiovascular risk equations, and formal cost-effectiveness and decision-curve analyses would together establish the place of the instrument in practice. Refinement using item-response theory could streamline the item set further, and integration into electronic dental and medical records would allow the score, and its trajectory over successive recalls, to flow automatically to the treating physician. Each of these steps builds toward a validated, scalable tool for interdisciplinary noncommunicable-disease prevention.

5. Conclusions

The ORCHID Index is a feasible, content-valid, internally consistent, and reliable single-page composite instrument that integrates oral disease burden with cardiometabolic and lifestyle risk into one thirty-point score, fulfilling the aim of this development and validation study. Its pilot performance supports its use as a rapid, jointly administered chairside tool, and its design squarely addresses a gap that established cardiovascular instruments leave open by bringing the oral domains they ignore into a single, actionable measure. By turning every dental visit into an opportunity for cardiovascular risk detection, the instrument offers a practical bridge between preventive dentistry and preventive cardiology, aligned with global and national policy that now places oral health within the noncommunicable disease agenda. Confirmation of its predictive value in longitudinal, multicentre research is the essential next step toward routine deployment.