This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for OSU Plate Waste Study (NCT02790502), a na na study. The primary outcome is Percent of Food Items Across All Participants That Were Not Fully Eaten Over Approximately 1 Week and That Were Not Kept as a Leftover for Subsequent Consumption..
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02790502 |
| Phase | NA |
| Condition | Plate Waste |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 18 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Pennington Biomedical Research Center |
| Results posted | Yes |
2. Clinical Question
Population
The registry record lists enrollment of 18 in a study concerning plate waste. Its primary measure combines food items across all participants. Further eligibility details and participant characteristics are not reported in the registry record.
Intervention
The intervention was the Food Photography Application©, identified as a device. Food waste was assessed using the Remote Food Photography Method (RFPM) over approximately 1 week. The registry record does not provide additional details about application use, training, or adherence.
Comparator
No comparator group is described. The study is recorded as single-group, and the allocation field is listed as NA. There is therefore no like-for-like control comparison in the registry record.
Primary question
The primary endpoint asks what percent of food items across all participants were not fully eaten during approximately 1 week and were not kept as leftovers for subsequent consumption. The observed percent is not reported in the registry record.
This question is descriptive: it concerns the proportion of recorded food items meeting the study’s definition of waste. It does not, by itself, establish whether using the application changed waste, because the registry record does not describe a separate comparison group or a before-and-after contrast. The study summary frames the project as testing a smartphone application for measuring household food waste. However, the registered endpoint is expressed across food items and participants, and the record does not report a direct measure of how accurately the method captured waste relative to another measurement approach.
The registry record identifies the sponsor as Pennington Biomedical Research Center and lists the study status as completed. It does not report enough information to determine which participants or food settings contributed to the recorded items, or whether the assessment period was identical for every participant. Those details matter for interpreting the population and scope to which a descriptive item-level percent could apply.
3. Trial Design
OSU Plate Waste Study is recorded as a completed, single-group study, with enrollment listed as 18. The intervention is the Food Photography Application©, categorized in the registry as a device. The study summary describes the project as testing a smartphone application for measuring household food waste. The primary outcome was assessed with the Remote Food Photography Method (RFPM) over approximately 1 week.
The registry lists allocation as NA and masking as NONE. It does not describe random assignment, a parallel control group, or another comparator. The registry record specifically indicates that this is not a randomized comparison and that any arms are not a like-for-like control comparison. The record lists an intervention group, but does not describe a separate control condition. Accordingly, the design supports a description of the measured food items, not a treatment-versus-control estimate.
The recorded start date is 2016-04-01, and the primary completion date is 2016-11-20. The study status is COMPLETED. The phase is listed as NA, which is consistent with the registry’s non-drug study details but does not supply further design information. The registry record does not report a protocol-level account of how participants were recruited, how long each person contributed observations, or whether the application was used in a standardized way.
The primary endpoint is an aggregate percent of food items across participants, rather than a participant-level average. The record notes that no measure of dispersion or precision is possible for this stated value because it simply reflects a percent of all items across all participants. The observed endpoint value itself is not reported in the registry record. A statistical analysis plan, sample-size justification, or interim analysis approach is also not reported in the registry record. The design therefore needs to be read as a limited descriptive measurement study, with important operational and analysis details unavailable.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Intervention |
|---|---|
| STARTED | 18 |
| COMPLETED | 18 |
| NOT COMPLETED | 0 |
5. Baseline Characteristics
The table reproduces the baseline characteristics posted in the registry, which describe the participants analysed at baseline and help show whether the randomized groups were comparable.
| Characteristic | Unit | Intervention |
|---|---|---|
| Participants analysed | 18 | |
| Age, Continuous | years | 50.8 (SD 8.2) |
| Sex: Female, Male: Female | Participants | 15 |
| Sex: Female, Male: Male | Participants | 3 |
| Race and Ethnicity Not Collected | Participants | — |
6. Primary Endpoint
The registry lists the primary outcome as Percent of Food Items Across All Participants That Were Not Fully Eaten Over Approximately 1 Week and That Were Not Kept as a Leftover for Subsequent Consumption., measured over 1 week.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Percent of foods across all participants |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the percent of food items across all participants that were not fully eaten over approximately 1 week and were not saved as leftovers for later consumption. Food waste was assessed using the Remote Food Photography Method (RFPM). The definition combines two criteria: an item was not fully consumed, and it was not kept for subsequent consumption. Food retained as a leftover is therefore excluded from the endpoint’s waste category even if it was not eaten at the initial meal.
An item-level percent can describe how frequently recorded foods met this operational definition within the observations. It is distinct from the percent of participants who wasted food, the amount of food discarded by weight, or the percent of meals with waste. The registry record does not state that these other quantities were measured as the primary endpoint.
This measure is relevant to the study’s stated aim of testing a smartphone application for measuring household food waste: photographic assessment can be used to record food and leftovers over time. That general rationale does not establish measurement accuracy. The registry record does not report a validation comparison, a reference measurement, or the observed endpoint value. It also states that no measure of dispersion or precision is possible for the reported aggregate-percent definition. As a result, the registered endpoint is interpretable as a descriptive summary, but the record does not permit an assessment of its uncertainty or of how well it generalizes beyond the observed items.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clear descriptive outcome, but it does not report the observed percent. The main numerical result needed to answer the primary question is therefore not reported in the registry record. The record also lists no analyses, and provides no inferential estimate, confidence interval, or p-value for the primary endpoint. Consequently, the primary outcome cannot be quantitatively interpreted from the information recorded.
Even if an aggregate percent were available, its interpretation would depend on the item-level observations and how they were collected. The endpoint counts food items across participants, so it does not directly describe the proportion of participants who experienced food waste. It also does not express the amount of wasted food by mass or value. The registry record supplies no item counts or other denominator details with which to assess the scale of the aggregate.
The study has a single-group design and no like-for-like control comparison. Thus, the recorded design does not establish whether food photography changed waste or whether the application performed better than another measurement method. There is no registered comparator against which to estimate a difference, and no baseline contrast is described. A descriptive observation from one group is not a causal estimate of an intervention effect.
The endpoint description says that no measure of dispersion or precision is possible because the value reflects a percent of all items across all participants. General statistical interpretation: a confidence interval is a way to express uncertainty around an estimate, under assumptions about how observations were sampled and related. For item-level observations, estimating uncertainty would require an appropriate analysis that accounts for the data structure, including whether items from the same participant are correlated. The registry record does not report such an analysis or the information needed to evaluate its assumptions. It would be inappropriate to infer precision from the enrollment figure alone.
The registry lists enrollment of 18 and study status as completed, but these registry entries do not establish that every participant contributed usable data for the primary endpoint. The number with outcome data and the handling of incomplete observations are not reported in the registry record. The adverse-event record lists 0 serious events, 0 other events, and 0 deaths in the intervention group, with 18 at risk for each recorded event category. These entries describe the registry’s safety reporting; they do not resolve the missing efficacy result or provide a comparison with another group.
Overall, the available record documents the study’s aim, intervention, and endpoint definition, but not the primary result or the analysis needed to quantify its uncertainty. No claim about the application’s effectiveness or measurement performance follows from the recorded information alone.
9. Statistical Methods Explained
What does the endpoint estimate?
The endpoint is a descriptive percent defined over food items across participants. Its numerator would correspond to items that were not fully eaten and were not saved for later consumption, while its denominator would correspond to the relevant food items assessed. The registry record does not report the observed percent or the underlying item counts. No numerator, denominator, or additional summary should be inferred from the listed enrollment.
General statistical explanation: a proportion summarizes the frequency of a condition among the observations included in its denominator. Its meaning depends on the unit of observation. Here, the unit is a food item, not a participant. Thus, a high or low item-level proportion would not directly translate into the same proportion of participants experiencing waste. Nor would it describe the weight, cost, or nutritional content of discarded food.
Why does the single-group design matter?
The registry records a single-group model, allocation as NA, and masking as NONE. It does not describe a control group or a randomized treatment contrast. General statistical explanation: a comparison group can help distinguish an intervention-associated change from other influences, such as changes over time or differences in who is observed. Without a comparator or a described pre-intervention measure, an outcome observed in one group is descriptive rather than a comparative effect estimate.
The intervention is the Food Photography Application©, and the summary describes testing a smartphone application for measuring household food waste. The primary outcome uses the Remote Food Photography Method (RFPM). The registry record does not explain whether the application itself is the means by which the endpoint was collected in every instance, nor does it describe a separate reference method. Accordingly, it does not support a conclusion about measurement agreement or validity.
What does precision mean for an aggregate percent?
The endpoint description explicitly says that no measure of dispersion or precision is possible for the stated value because it is a percent of all items across all participants. General statistical explanation: an uncertainty interval usually requires a sampling model and information about the variation among observations. When multiple observations come from the same person, they may be more alike than observations from different people. Treating all items as independent could therefore misstate uncertainty. Methods that account for clustering may be appropriate in some settings, but the registry record does not report such a method or the data needed to evaluate it.
A confidence interval would communicate how uncertain an estimate is under an analysis model; it would not correct an unsuitable endpoint definition, incomplete measurement, or lack of a comparison group. In this study, the registry reports neither an observed primary value nor a confidence interval. It is therefore not possible to assess the magnitude or precision of the endpoint from the registry record.
What analyses are documented?
The record lists no analyses. It does not report a statistical analysis plan, a model for the primary endpoint, a hypothesis test, or a method for handling missing observations. No interim analysis approach is reported in the registry record. These omissions mean that the analysis decisions cannot be assessed and that no inferential result can be reconstructed from the registered information.
The record includes a general planning illustration description based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It describes the effect to detect as a stated fraction of the observed effect. Those are assumptions for a planning illustration, not evidence that the actual study used two arms or a randomized comparison; its recorded model is single-group. No numerical planning results are reported in the registry record. A planning illustration is not observed power and does not substitute for results from the completed study.
How should the result be assessed?
General statistical explanation: statistical interpretation should distinguish the estimate, its uncertainty, the data structure, and the design. A descriptive estimate can be useful for documenting observed items, while causal interpretation requires a design and analysis that support a comparison. Precision depends on the observations and their dependence, not simply on the enrollment figure. The registry record does not supply the endpoint estimate, data counts, or an inferential analysis needed for these assessments.
The record’s stated endpoint definition and method remain useful for understanding what was intended to be measured. However, the absent observed percent means the primary research question cannot be answered quantitatively from this registry entry. The lack of analysis details also prevents an independent assessment of whether methods were appropriate for the item-level data.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists one primary outcome measure and no analyses. It does not report additional outcome tests, subgroup analyses, multiple time points, or an adjustment for multiple comparisons. A multiplicity strategy is therefore not reported in the registry record. With no reported inferential results, there is no basis for evaluating whether multiple testing affected the interpretation.
Missing-data methods are also not reported in the registry record. The enrollment figure does not indicate how many participants contributed primary-outcome observations, whether all planned observations were captured, or how incomplete food photographs or unclassifiable items were handled. The record does not describe imputation, exclusion rules, or sensitivity analyses. These details matter because missing observations can influence a descriptive proportion if the missingness is related to whether food was consumed or saved.
The analysis population is not defined in the registry record. It is not stated whether the primary endpoint was intended to include all enrolled participants, only participants who used the application, or only those with complete assessment data. The record also does not give a participant flow or an item-level accounting of included observations. No assumptions about analysis populations or missingness should be inferred from the completed status or enrollment listing.
Since no primary result or analysis is reported, statistical handling of multiplicity and missing data cannot be assessed. The registry record does not report an interim analysis plan or broader statistical analysis plan either.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| Intervention | 0 | 18 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Intervention | 0 of 18 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| Intervention | 0 of 18 |
The serious adverse-event record lists the intervention group with 18 at risk and 0 serious events. It also records 18 at risk and 0 other events, and 0 deaths. No serious adverse-event terms are listed. These entries are the safety figures recorded for the intervention group.
Zero recorded events should be read as a registry count, not as proof that no adverse events could occur or that the intervention has been established as safe. The registry record does not provide further detail about how events were solicited, defined, monitored, or attributed, and it offers no comparison group. Without a comparator, the record cannot support a comparative safety estimate. The listed at-risk figures describe the registry’s reporting fields; they do not establish that all enrolled participants completed the same duration of safety monitoring.
These safety entries are separate from the primary food-waste endpoint. They do not supply the missing endpoint result, and they do not indicate whether the application successfully measured food waste.
12. What the Result Does, and Does Not, Mean
The registry record documents a completed, single-group study of the Food Photography Application© and a primary endpoint intended to describe food items not fully eaten and not kept as leftovers over approximately 1 week. The method named for the assessment is the Remote Food Photography Method (RFPM). These details clarify the measurement question and the study’s general purpose.
The observed value of the primary endpoint is not reported in the registry record. The record also provides no analysis result, confidence interval, or p-value. It therefore does not show the measured proportion of items meeting the waste definition, nor does it quantify uncertainty around that proportion. The enrollment listing alone cannot replace these missing results.
The design does not include a reported like-for-like control comparison. It cannot establish that the application caused a change in food waste, and it cannot show that this method performs better than an alternative measurement approach. The registry record does not report a validation comparison or accuracy result. The endpoint is an item-level percent, not a measure of participants who wasted food or the amount discarded by weight.
The listed safety record contains 0 serious events, 0 other events, and 0 deaths in the intervention group. These counts are limited to the registry’s reported safety categories and are not a comparative safety assessment.
In sum, the record identifies what the investigators aimed to measure and how the primary outcome was defined, but it does not provide the principal observed result. It supports no conclusion about the magnitude of food waste in the observed items, the application’s effect on waste, or the method’s measurement performance.
13. Why This Trial Matters Statistically
This study raises a useful statistical distinction between measuring an outcome and estimating an intervention effect. A photographic method may be intended to record food consumption and leftovers, but assessing an intervention’s effect requires a suitable comparison and a reported outcome analysis. The registry record describes a single-group design without a like-for-like control comparison, so its design is primarily descriptive.
The endpoint’s unit also matters. The primary measure is a percent of food items across participants. Item-level summaries can answer questions about recorded items, but they do not automatically answer participant-level questions. Multiple items may come from the same person, making observations potentially related. General statistical reasoning therefore calls for care in defining the denominator and in assessing uncertainty, especially when observations are clustered. The registry record itself notes that no measure of dispersion or precision is possible for its aggregate-percent outcome.
The record illustrates why complete reporting is necessary for statistical interpretation. Although the endpoint definition and assessment period are stated, the observed percent, underlying item counts, analysis, and missing-data handling are not reported in the registry record. Without those elements, readers cannot evaluate the magnitude of the result, its precision, or the sensitivity of conclusions to analytic choices.
The study summary situates the work in the broader challenge of measuring food waste. Statistically, the record is informative about the intended measurement question and the limits imposed by a single-group design, but the absent primary result prevents assessment of what the study observed. A clearly defined outcome is important; transparent outcome reporting and analysis are also needed to make that definition empirically useful.
14. Limitations
- The posted summary statistics are the only data these results rest on; patient-level data, full protocols and statistical analysis plans are not available.
- Recalculated results are simple, unadjusted calculations from posted summaries. They do not replace the sponsor's prespecified analysis.
The primary limitation for interpretation is that the observed endpoint value is not reported in the registry record. The record provides no item counts, denominator details, or inferential analysis, so the primary question cannot be answered quantitatively from the entry.
The study is recorded as single-group, with allocation listed as NA and masking as NONE. No like-for-like comparator is described. The design therefore does not support a comparative intervention-effect estimate. The registry record also does not describe a reference measurement against which the Remote Food Photography Method (RFPM) or application could be evaluated for accuracy.
The primary outcome is a percent of food items across all participants, but the record does not report how items were sampled, classified, or aggregated. The endpoint description states that no measure of dispersion or precision is possible for this aggregate value. The record does not supply detail about within-participant dependence, item-level missingness, or how incomplete records were handled. Participant characteristics, eligibility criteria, and the number contributing usable endpoint data are not reported in the registry record.
The registry does not provide a statistical analysis plan, model, analysis population, missing-data approach, or interim analysis approach. It is therefore not possible to assess whether the intended methods accounted for clustering or other features of the observations. The completed status and enrollment listing do not resolve these reporting gaps.
Finally, the safety record has no comparator and contains only registry event counts. It does not provide detailed monitoring procedures or support a comparative assessment. These design and reporting limitations are specific to interpreting the recorded outcome and should not be mistaken for evidence about unreported results.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: OSU Plate Waste Study — NCT02790502.
- Registry record last updated 2025-01-01; status last verified 2024-12.
- Results first posted 2025-01-01.
- Data retrieved from ClinicalTrials.gov on 2026-11-09.
- Group sizes, means, event counts and sponsor-reported p-values are reproduced as posted. Effect estimates, confidence intervals and p-values not attributed to the sponsor are independently calculated from the posted summary statistics.
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18. Record Summary
OSU Plate Waste Study (NCT02790502) is recorded as completed. The sponsor is Pennington Biomedical Research Center. The registry lists a start date of 2016-04-01, primary completion date of 2016-11-20, and enrollment of 18.
The study is classified as single-group, with allocation listed as NA and masking as NONE. The intervention is the Food Photography Application©. Food waste was assessed using the Remote Food Photography Method (RFPM) over approximately 1 week. The primary endpoint is the percent of food items across participants that were not fully eaten and were not kept as leftovers.
The observed primary endpoint value and analysis results are not reported in the registry record. The safety record lists 0 serious events, 0 other events, and 0 deaths in the intervention group.