Related Experiment Video
Updated: Feb 9, 2026

A Retrospective Study on Endoscopic Surgery for the Treatment of Paravertebral Abscess in Spinal Tuberculosis Patients
Published on: October 25, 2024
Considering Spine Surgery: A Web-Based Calculator for Communicating Estimates of Personalized Treatment Outcomes
Haley Moulton1, Tor D Tosteson1, Wenyan Zhao1
1Geisel School of Medicine, Hanover, NH.
Study Design:
Prospective evaluation of an informational web-based calculator for communicating estimates of personalized treatment outcomes.
Objective:
To evaluate the usability, effectiveness in communicating benefits and risks, and impact on decision quality of a calculator tool for patients with intervertebral disc herniations, spinal stenosis, and degenerative spondylolisthesis who are deciding between surgical and nonsurgical treatments.
Summary Of Background Data:
The decision to have back surgery is preference-sensitive and warrants shared decision making. However, more patient-specific, individualized tools for presenting clinical evidence on treatment outcomes are needed.
Methods:
Using Spine Patient Outcomes Research Trial data, prediction models were designed and integrated into a web-based calculator tool: http://spinesurgerycalc.dartmouth.edu/calc/. Consumer Reports subscribers with back-related pain were invited to use the calculator via email, and patient participants were recruited to use the calculator in a prospective manner following an initial appointment at participating spine centers. Participants completed questionnaires before and after using the calculator. We randomly assigned previously validated questions that tested knowledge about the treatment options to be asked either before or after viewing the calculator.
Results:
A total of 1256 consumer reports subscribers and 68 patient participants completed the calculator and questionnaires. Knowledge scores were higher in the postcalculator group compared to the precalculator group, indicating that calculator usage successfully informed users. Decisional conflict was lower when measured following calculator use, suggesting the calculator was beneficial in the decision-making process. Participants generally found the tool helpful and easy to use.
Conclusion:
Although the calculator is not a comprehensive decision aid, it does focus on communicating individualized risks and benefits for treatment options. Moreover, it appears to be helpful in achieving the goals of more traditional shared decision-making tools. It not only improved knowledge scores but also improved other aspects of decision quality.
Level Of Evidence:
2.
Related Concept Videos
Communication
Communication
Titration Calculations: Weak Acid - Strong Base
For the titration of 25.00 mL of 0.100 M CH3CO2H with 0.100 M NaOH, the reaction can be represented as:
Titration Calculations: Strong Acid - Strong Base
A titration is carried out for 25.00 mL of 0.100 M HCl (strong acid) with 0.100 M of a strong base NaOH. The pH at different volumes of added base solution can be calculated as follows:
(a) Titrant volume = 0 mL. The solution pH is due to the acid ionization of HCl. Because this is a strong acid, the ionization is complete and the hydronium ion molarity is 0.100 M. The pH of the solution is then:
Calculating pH Changes in a Buffer Solution
Calculating the Equilibrium Constant
For example, gaseous nitrogen dioxide forms dinitrogen tetroxide according to this equation:

