Abstract
Very Productive Score was generally 245% higher than average after an average of 172 pounds of Body Weight over the previous 7 days.
Aggregated data from 3 study participants suggests with a HIGH degree of confidence (p=0.00192, 95% CI -2.528 to 2.598) that Body Weight has a very weakly positive predictive relationship (R=0.0351) with Very Productive Score.
The highest quartile of Very Productive Score measurements were observed following an average 177 pounds Body Weight.
The lowest quartile of Very Productive Score measurements were observed following an average 178 pounds of Body Weight.
After an onset delay of 0 seconds, Very Productive Score is typically 58% lower than average over the 7 days following around 178 pounds of Body Weight Body Weight.
Keywords: Body Weight, Very Productive Score, N-of-1 trials, real-world evidence, causal inference, observational study
Preliminary: Based on 3 participants. Results may change as more data is collected.
Results
Primary Findings
Analysis of 534 paired observations from 3 participants revealed a minimal improvement in Very Productive Score following above-average Body Weight exposure.
Supporting Statistics
What This Means
When participants had above-average Body Weight:
- Very Productive Score increased by 0.3% on average
- Temporal analysis supports Body Weight as the predictor (not the outcome)
Interpreting the Predictor Impact Score
The Predictor Impact Score (PIS) integrates multiple Bradford Hill causal criteria into a single metric. Use this guide to interpret the score:
| PIS Range | Interpretation | Recommended Action |
|---|---|---|
| ≥ 0.5 | Strong evidence | High priority for RCT validation |
| 0.3 - 0.5 | Moderate evidence | Consider for experimental investigation |
| 0.1 - 0.3 | Weak evidence | Monitor for additional data |
| < 0.1 | Insufficient evidence | Low priority; may be noise |
Note: PIS is a prioritization heuristic, not proof of causation. High scores indicate relationships worth investigating, not confirmed causal effects. With only 3 participants, these scores are preliminary and will become more reliable as additional data is collected.
Optimal Daily Values
No clear dose-response relationship detected. The Body Weight values associated with high and low Very Productive Score are too similar to provide meaningful dosing guidance. This may indicate a threshold effect (any amount works equally well), no effect, or insufficient data variance. With more participants, a clearer pattern may emerge.
Population Correlation
Trait Correlation Between Body Weight and Very Productive Score
Body Weight Distribution
Daily Distribution
Average by Day of Week
Average by Month
Average by Year
Very Productive Score Distribution
Daily Distribution
Average by Day of Week
Average by Month
Average by Year
Relationship Analysis
Very Productive Score Following Body Weight
Correlation Between Body Weight and Very Productive Score by Duration of Action
Correlation Between Body Weight and Very Productive Score by Onset Delay
Average Body Weight Preceding Very Productive Score
Average Very Productive Score by Previous Body Weight
Statistical Summary
Relationship Statistics
| Property | Value |
|---|---|
| Cause Variable Name | Body Weight |
| Effect Variable Name | Very Productive Score |
| Sinn Predictive Coefficient | 0.0045486404657142 |
| Confidence Level | HIGH |
| Confidence Interval | 2.5631951365816 |
| Forward Pearson Predictive Coefficient | 0.0351 |
| Critical T Value | 1.6506666666667 |
| Average Body Weight Over Previous 7 days Before ABOVE Average Very Productive Score | 177 pounds |
| Average Body Weight Over Previous 7 days Before BELOW Average Very Productive Score | 178 pounds |
| Duration of Action | 7 days |
| Effect Size | very weakly positive |
| Number of Paired Measurements | 534 |
| Optimal Pearson Product | 0.60801132439431 |
| P Value | 0.0019207109563234 |
| Statistical Significance | 0.8187 |
| Strength of Relationship | 2.5631951365816 |
| Study Type | population |
| Analysis Performed At | 2026-01-04 |
| Number of Participants | 3 |
Body Weight Info
| Property | Value |
|---|---|
| Variable Name | Body Weight |
| Aggregation Method | MEAN |
| Analysis Performed At | 2020-09-23 |
| Duration of Action | 7 days |
| Kurtosis | 29.271534088526 |
| Maximum Allowed Value | 1000 pounds |
| Mean | 168.9619340574 pounds |
| Median | 168.27481272906 pounds |
| Minimum Allowed Value | 0 pounds |
| Number of Aggregate Predictors | 883 |
| Number of Aggregate Outcomes | 257 |
| Number of Measurements | 108822 |
| Number of Measurements (including those generated by tagged, joined, or child variables) | 21092 |
| Public | true |
| Onset Delay | 0 seconds |
| Standard Deviation | 8.7190661755282 |
| Unit | Pounds |
| User Variables | 417 |
| UPC | 875011003902 |
| Variable Category | Physique |
| Variable ID | 1486 |
| Variance | 594.35417755402 |
Very Productive Score Info
| Property | Value |
|---|---|
| Variable Name | Very Productive Score (Rating) |
| Aggregation Method | MEAN |
| Analysis Performed At | 2020-10-11 |
| Duration of Action | 7 days |
| Kurtosis | 15.991447741274 |
| Mean | 17.41425808522 percent |
| Median | 1.6499715874074 percent |
| Number of Aggregate Predictors | 597 |
| Number of Aggregate Outcomes | 27 |
| Number of Measurements | 3795 |
| Number of Measurements (including those generated by tagged, joined, or child variables) | 456 |
| Public | true |
| Onset Delay | 0 seconds |
| Standard Deviation | 36.773532978965 |
| Unit | Percent |
| User Variables | 27 |
| Variable Category | Goals |
| Variable ID | 6051179 |
| Variance | 2760.2835632428 |
Introduction
Background
Body Weight (Physique) and Very Productive Score (Goals) are both important factors in understanding human health and well-being. This study investigates the relationship between these two variables using real-world observational data.
Traditional randomized controlled trials (RCTs), while the gold standard for causal inference, are often impractical, expensive, or unethical for studying many health relationships. Aggregated N-of-1 observational studies offer a complementary approach that leverages within-subject comparisons across large populations to identify meaningful patterns.
Research Question
Does Body Weight affect Very Productive Score?
Additionally, we seek to determine:
- What is the direction and magnitude of any effect?
- How confident can we be in this relationship based on the available data?
- What are the optimal levels of Body Weight for maximizing Very Productive Score?
Study Objective
The objective of this study is to determine the nature of the relationship (if any) between Body Weight and Very Productive Score. Additionally, we attempt to determine the Body Weight values most likely to produce optimal Very Productive Score values.
Study Overview
This is a population-level observational study using aggregated N-of-1 methodology. By aggregating individual N-of-1 experiments, we can identify population-level patterns while accounting for the substantial individual variation that exists in most health relationships. Effect sizes are reported as percent change from baseline, enabling intuitive interpretation and comparison across different measures.
Full Methodology: Framework for Real-World Evidence-Based Pharmacovigilance: Aggregated N-of-1 Trials for Quantifying Treatment Effects
Discussion
Interpretation of Findings
Participants experienced a 0.3% improvement in Very Productive Score following above-average Body Weight exposure. The Predictor Impact Score (PIS) of 0.00 indicates insufficient evidence for a causal relationship.
Statistical Significance
Using a two-tailed t-test with alpha = 0.05, it was determined that the change in Very Productive Score is statistically significant at a 95% confidence interval. The p-value of 0.8187 indicates there is less than a 81.87% probability that this result occurred by chance.
After treatment, a 6% increase (0.322 percent) from the mean baseline 3.68 percent was observed. The relative standard deviation at baseline was 2.06667%. The observed change was 11.322 times the standard deviation.
A common rule of thumb considers a change greater than twice the baseline standard deviation on two separate pre-post experiments may be considered significant. This occurrence would have only a 5% likelihood of resulting from random fluctuation (a p-value < 0.05).
T-Test Details
Since t = 5.70 > 1.65, we reject the null hypothesis.
Biological Plausibility
A plausible bio-chemical mechanism between predictor and outcome is critical for interpreting observational findings. This is where human judgment excels beyond statistical analysis.
Community feedback on the biological plausibility of this relationship is still being collected. Consider the known mechanisms by which Body Weight might influence Very Productive Score.
Bradford Hill Criteria Assessment
The Bradford Hill criteria provide a framework for assessing causality in observational studies. Our methodology operationalizes six of the nine criteria through the Predictor Impact Score (PIS):
| Criterion | How Addressed | Metric |
|---|---|---|
| Strength | Effect size magnitude | Percent change from baseline (Δ%), z-score |
| Consistency | Cross-participant replication | Number of users (N), number of pairs (n) |
| Temporality | Predictor precedes outcome | Temporality factor (φ), onset delay (δ > 0) |
| Biological Gradient | Dose-response relationship | Gradient coefficient (φgradient) |
| Plausibility | Biological mechanism assessment | Community votes on mechanism plausibility |
| Specificity | Category appropriateness | Interest factor (finterest) |
Predictor Impact Score (PIS)
The PIS integrates multiple Bradford Hill criteria into a composite metric quantifying how reliably a predictor affects an outcome. Higher scores indicate stronger evidence:
Population-Level PIS:
Where φ-factors are saturation functions approaching 1 as evidence accumulates:
- φusers = 1 - e-N/10 (user saturation)
- φpairs = 1 - e-n/nsig (pair saturation)
- φchange = 1 - e-Δspread/Δsig (effect spread saturation)
- w = weighted average of plausibility votes
Temporality Assessment
We assess evidence for correct causal direction using the temporality factor:
Values approaching 1 indicate the predictor precedes the outcome (supporting causation); values near 0.5 suggest ambiguous directionality; values near 0 suggest reverse causation or confounding by indication.
Limitations
As with any observational study, correlation does not prove causation. Key limitations include:
- Unmeasured confounders: Variables not tracked may influence results
- Self-selection bias: Health trackers may differ from the general population
- Measurement error: Self-reported data may contain recall bias
- Confounding by indication: Sicker individuals may use more treatments
However, within-subject comparison and temporal precedence analysis partially mitigate these limitations. If the relationship is merely coincidental, as participants independently modify their Body Weight values, the observed strength will decline over time. Spurious correlations naturally dissipate as more data is collected.
Future Directions
Future research should examine:
- Subgroup analyses to identify individual differences in response
- Potential confounders and mediators of the observed relationship
- Optimal dosing and timing for Body Weight
- Confirmation through prospective or randomized designs
- Biological mechanisms underlying the observed effects
Conclusion
📊 Preliminary Findings: With 3 participants, these results are based on limited data. Effect sizes and confidence will improve as more participants contribute data. Consider these findings directional rather than definitive.
Above-average Body Weight was associated with a 0.3% improvement in Very Productive Score—a minimal effect. The Predictor Impact Score of 0.00 indicates this relationship is requiring additional data before conclusions.
Bottom Line: Based on a PIS of 0.00 and a 0.3% effect size, this relationship currently lacks sufficient evidence. Continue monitoring as more data becomes available. Note: These conclusions may strengthen or change direction as more data is collected.
These findings contribute to our understanding of how Body Weight may influence Very Productive Score in real-world conditions. While preliminary, these results may inform future research directions. As more participants contribute data, the reliability and precision of these findings will improve substantially.
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Methods
Study Design
This study is based on data donated by 3 participants. Thus, the study design is equivalent to the aggregation of 3 separate n=1 observational natural experiments.
This within-subject design is powerful because it controls for all stable individual characteristics (genetics, baseline health status, socioeconomic factors) that might otherwise confound the relationship between variables.
Data Analysis
Temporal Assumptions
The analysis incorporates temporal assumptions about the relationship between variables:
- Onset Delay: It was assumed that 0 seconds would pass before a change in Body Weight would produce an observable change in Very Productive Score.
- Duration of Action: It was assumed that Body Weight could produce an observable change in Very Productive Score for as much as 7 days after the stimulus event.
Statistical Methods
For each participant, we calculated the Pearson correlation coefficient between Body Weight values and subsequent Very Productive Score values. Individual correlations were then aggregated using Fisher's z-transformation to produce a population-level estimate:
Individual Correlation:
Fisher's Z-Transformation:
Aggregated Correlation:
Effect Size Calculation
Effect sizes are reported as percent change from baseline. For each participant, we compare the outcome following above-average predictor values to the overall baseline outcome:
Effect Magnitude (Z-Score)
To assess effect magnitude relative to natural variability, we calculate the z-score:
where RSDbaseline is the relative standard deviation of outcome during baseline period
A z-score > 2 indicates statistical significance (p < 0.05), meaning the observed change exceeds typical baseline fluctuation and is unlikely due to random variation.
Statistical Significance
Correlation significance is assessed using a two-tailed t-test:
We reject the null hypothesis (ρ = 0) at α = 0.05 when |t| exceeds the critical value, providing statistical evidence that the observed relationship is not due to chance.
Data Sources
Body Weight data was primarily collected using Fitbit. Fitbit makes activity tracking easy and automatic.
Very Productive Score data was primarily collected using RescueTime. Detailed reports show which applications and websites you spent time on. Activities are automatically grouped into pre-defined categories with built-in productivity scores covering thousands of websites and applications. You can customize categories and productivity scores to meet your needs.
Data Quality
Data quality measures were applied to ensure reliable results:
- Minimum Data Requirement: Only participants with sufficient paired observations were included in the analysis.
- Outlier Handling: Extreme values were winsorized to reduce the influence of measurement errors.
- Missing Data: Days with missing values were handled using appropriate filling strategies based on the variable type.
- Test User Exclusion: Test accounts and invalid users were excluded from all analyses.
Principal Investigator
Program & Methods
Cite This Study
@misc{sinn_cause_1486_effect_6051179_population_study_2026,
author = {Sinn, Mike P.},
title = {Causal Analysis: Does Body Weight Affect Very Productive Score (Rating)?},
year = {2026},
publisher = {The Journal of Citizen Science},
url = {https://studies.crowdsourcingcures.org/study/cause-1486-effect-6051179-population-study},
note = {Accessed: January 11, 2026}
}
Study Type: Aggregated N-of-1 Observational Mega-Study
Evidence Level: Level II (Real-World Evidence)
Methodology: Bradford Hill Criteria with Predictor Impact Score (PIS)
References
This framework was originally developed in 2013 based on the Bradford Hill criteria. Subsequent literature has independently validated similar approaches to causal inference from observational data:
- Hill, A.B. (1965). The environment and disease: association or causation? Proceedings of the Royal Society of Medicine, 58(5), 295-300. [Bradford Hill criteria]
- Lillie, E.O., et al. (2011). The n-of-1 clinical trial: the ultimate strategy for individualizing medicine? Personalized Medicine, 8(2), 161-173. [N-of-1 methodology]
- Pearl, J. (2009). Causality: Models, Reasoning, and Inference . Cambridge University Press. [Causal inference]
- Hernán, M.A., & Robins, J.M. (2020). Causal Inference: What If . Chapman & Hall/CRC. [Free textbook]
- FDA (2018). Framework for FDA's Real-World Evidence Program . U.S. Food and Drug Administration. [Regulatory context]
- Duan, N., et al. (2013). Single-patient (n-of-1) trials: a pragmatic clinical decision methodology . Journal of Clinical Epidemiology, 66(8), S21-S28.
- Platt, R., et al. (2018). The FDA Sentinel Initiative—an evolving national resource . New England Journal of Medicine, 379(22), 2091-2093.
This information is for research and educational purposes only, not medical advice. Consult a healthcare provider before making health decisions. Terms of Service