DLNM Model Specification

Specify and fit Distributed Lag Non-Linear Models for time series regression.

Updated Mar 7, 2026
One-click install
npx skills add https://github.com/ntluong95/agent-skills-statistics --skill dlnm-model-specification
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: DLNM Model Specification
Source: https://github.com/ntluong95/agent-skills-statistics/tree/main/skills/dlnm/model-specification
Command: npx skills add https://github.com/ntluong95/agent-skills-statistics --skill dlnm-model-specification

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill simplifies the process of specifying and fitting complex Distributed Lag Non-Linear Models (DLNMs) for time series data, particularly in environmental epidemiology.

Core Features & Use Cases

  • Canonical Model Structure: Provides a template for fitting GLMs with cross-basis terms, time trends, and confounders.
  • Outcome & Family Guidance: Recommends appropriate families (quasi-Poisson, Poisson, negative binomial) based on outcome type and over-dispersion.
  • Confounding Control: Details strategies for adjusting for time trends, seasonality, meteorological factors, and other temporal confounders.
  • Use Case: Fit a quasi-Poisson GLM to daily mortality data, including a DLNM for temperature, natural splines for long-term trends and day-of-week, and a separate spline for daily temperature.

Quick Start

Fit a DLNM model for daily deaths using cross-basis for temperature, natural splines for time and temperature, and day of week.

Frequently Asked Questions about DLNM Model Specification

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I specify a DLNM time series model for environmental epidemiology data?

To specify a DLNM time series model, use a GLM with cross-basis terms for exposure-lag-response relationships, natural cubic splines for temporal trends, and quasi-Poisson families for over-dispersed count outcomes like daily mortality data.

When should I use quasi-Poisson instead of Poisson in a time series regression?

Use quasi-Poisson in time series regression when modeling over-dispersed count outcomes, such as daily deaths or hospital admissions. It adjusts the standard errors appropriately, whereas standard Poisson assumes the mean and variance are strictly equal.

How do I control for confounding in a distributed lag non-linear model?

Control confounding in a DLNM by adding natural cubic splines for long-term trends and seasonality, incorporating day-of-week effects as categorical variables, and including separate splines for meteorological factors like daily temperature.

Can I fit a DLNM with negative binomial regression instead of quasi-Poisson?

Yes, you can fit a DLNM using negative binomial regression instead of quasi-Poisson for over-dispersed count data. The model supports Poisson, quasi-Poisson, and negative binomial families depending on your outcome type and variance structure.

What is the best way to model temperature's lagged effects on daily mortality?

Model temperature's lagged effects on daily mortality by fitting a quasi-Poisson GLM with a cross-basis function for temperature, natural splines for long-term time trends, and indicator variables for day-of-week to adjust for temporal confounding.