Medical device filing citing a New England Journal of Medicine paper — Tandem Diabetes CARE, 2019-12-13
Tandem Diabetes CARETandem Diabetes CARENASDAQ TNDM
Filings SEC · Quote Yahoo cited a paper published in the New England Journal of Medicine as the basis for its claims in a regulatory filing with the U.S. Securities and Exchange CommissionU.S. Securities and Exchange Commission
Regulator · Website. The company read the way it wrote the paper and the actual scope of the paper in order. The stock price movement for one month after the filing was compared to past cases of the same type. This is a retrospective judgment written after knowing the results. The paper was read only up to the abstract.
The disclosure is written in the press release as follows:
When a U.S. listed company has an event to inform shareholders, it files a 8-K with the Securities and Exchange Commission. Tandem Diabetes CARE filed this document on 2019-12-13, and the item number was 8.01 Other Events. The company cited a paper published in New England Journal of Medicine in the press release attached to it. If you translate the sentence citing the paper verbatim, it reads as follows.
Control-IQ Technology - Clinical Outcomes Data from the NIH-funded DCLP3 study, published by the New England Journal of Medicine in October 2019, compared use of a t:slim X2 insulin pump with Control-IQ technology and Dexcom G6 CGM integration (n=112) to a control group using a t:slim X2 pump with just Dexcom G6 CGM integration (n=56). 8 This study was the first large-scale 6-month closed loop study to include a dedicated control group.
What readers should first check is where the company placed the paper in the press release. Next, they should determine whether the paper supports the entire company claim or only a part of it. To answer the latter question, one must read the full paper. This article, which has only read the abstract, cannot provide an answer to that.
The scope of the paper discussed in the abstract is limited to this.
The paper's title is Six-Month Randomized, Multicenter Trial of Closed-Loop Control in Type 1 Diabetes and it was published in New England Journal of Medicine on 2019-10-16. The authors are affiliated with Diabetes Australia, University of Virginia, Jaeb Center for Health Research, and Stanford University. The summary at the beginning of the paper is called abstract. This article has only read up to that point. The paragraph was written by a person after filtering a draft generated by a machine through numerical comparison, so it is of a different grade than a full reading of the paper.
It is a multi-center randomized trial comparing a closed-loop system that automatically adjusts insulin infusion with existing pumps equipped with sensors in type 1 diabetes patients over six months. 168 participants were divided into two groups, with 112 receiving automated adjustment. The primary outcome was the proportion of time blood glucose levels measured by continuous glucose monitoring remained within the target range. Since the trial lasted six months, the effects and safety of longer-term use are not included in this paper.
What the abstract does not answer remains in the full paper and its appendices. This article, which has not gone beyond the abstract, leaves the gaps as they are. Readers should determine which sentence in the abstract corresponds to the cited section cited by the company by comparing the two citations above.
One month later, the stock price was within the middle half of the sample.
The remaining return after subtracting the portion that moves with the overall market is called excess return. The date is written as trading day, counting only the days the stock market is open. In terms of the calendar, 20 trading days are about a month. The excess return for the day of the regulatory filing and the following month are listed in the table below.
| Period | Excess return relative to the market | Meaning |
|---|---|---|
| Five trading days before the filing | −9.2% | The extent of movement before the filing |
| On the day of the filing | +5.4% | On the filing day or the first trading day after |
| Accumulated over +1 to +5 trading days | +4.0% | One week |
| +1~+20 trading days cumulative | +3.6% | One month |
A bundle of past cases of the same type is called a sample. The position counted from the bottom is expressed as a percentile. The one-month excess return of +3.6% in this case is within the bottom 70% of the 142 samples, but still within the top half.
| Sample scale (20 trading days) | Tenth from the bottom | Fourth from the bottom | median | top 25% | top 10% | This case |
|---|---|---|---|---|---|---|
| Excess return | −31.9% | −20.1% | −7.4% | +5.5% | +19.5% | +3.6% |
Half of the sample falls between the two marks in the middle of the table. One checks from the table whether this case is inside or outside. The sample collects cases where U.S. listed companies wrote papers in 8-K over the past ten years. The company itself is excluded from the sample. The numbers written here are past facts, not rules to apply to the next case.
After the disclosure, the company issued such documents
After the disclosure date, the company issued three 8-K filings, listed only by item numbers. In 8-K filings without titles, the item number indicates the type of content. One can determine whether it was an earnings announcement or a contract based on that number. What exactly occurred is read in the original text of each link.
- 2020-02-24 8-K Item 2.02, 5.02 — Earnings Announcement · Executive and Director Changes
- 2020-04-30 8-K Item 2.02 — Earnings Announcement
- 2020-05-15 8-K Items 1.01,2.03,3.02 — Material Contract Execution · Debt Incurrence · Sale of Unregistered Securities
What this article does not answer
This article, which reads only the abstract, does not answer what method the paper used, what it reviewed, and how far it showed. How many times the paper cited by the company was cited afterward can be checked again through the OpenAlexOpenAlex
Data source · Website citation count. What will be seen next is whether the company's next 8-K again cites the same paper.
Glossary
- 8-K
- A voluntary report submitted to the Securities and Exchange Commission when a U.S. listed company has something to inform shareholders. It is categorized by item numbers such as earnings, contracts, and executive changes. All events in this article come from this document.
- Excess return
- The remainder after subtracting the overall market return from the stock return. It is used to see the movement of the company alone by removing the portion where the market as a whole rises or falls.
- Trading day
- A date counting only days when the stock market is open. Since weekends and holidays are excluded, 20 trading days correspond to roughly one calendar month.
- Sample and percentile
- A bundle of past cases of the same type is a sample, and the position from the bottom is expressed as a percentile. A percentile of 10 means that nine out of ten cases performed better than this case.
- Abstract
- An abstract is placed at the beginning of a paper. The author writes in a few sentences what was done, how it was done, and what results were obtained. Without reading the full text, one cannot know the details or limitations of the methods.