Table 4.

Study characteristics of included articles

Ref	Author	Year	Study design	Diabetes type	Type of complication	Sample size	Data collection period	Region
[28]	Abdi et al.	2012	RCT	1 and 2		350	***	Southern India
[29]	Adiga et al.	2010	CS	2		238	2008	Karnataka
[30]	Bjork et al.	2003	CS	1 and 2		5516	Jan-Sep 1999	National
[31]	Grover et al.	2005	COH	1 and 2		50	***	Northern India
[32]	Joshi et al.	2013	CS	2		166	Feb-Apr 2010	Punjab
[33]	Kuchake et al.	2010	CS	2		163	Jul 2009- Feb 2010	Maharashtra
[34]	Kumar et al.	2008	COH	2		819	2005	Delhi
[35]	Kumpatla et al.	2013	CC	2		368	Jun 2008-dec 2009	Chennai
[36]	Ramachandran et al.	2007	CS	2		556	1998 - 2005	7 states
[37]	Rao et al.	2011	CS	**		1858	Jan - Jun 2004	National
[38]	Rayappa et al.	1999	CS	1 and 2		611	1997 - 1998	Bangalore
[39]	Shivaprakash et al.	2012	COH	1 and 2		200	2005 and 2010	Mangalore
[40]	Shobhana et al.	2000	CC	2		270	Jan - Jun 1998	Chennai
[41]	Shobhana et al.	2002	CS	1		209	Jan - Oct 2000	Chennai
[42]	Shobhana et al.	2000	CS	2		596	1999	Chennai
[43]	Tharkar et al.	2010	CS	2*		718	Aug -Dec 2009	Chennai
[44]	Akari et al.	2013	COH	1 and 2		150	Feb-July 2012	Hanamkonda
[45]	Satyavany et al.	2014	CS	2		209	Aug 2008- Jan 2010	**
[46]	Tharkar et al.	2009	CS	2		443	Oct- Dec 2007	**

CC = Case Control Study CS = Cross Sectional Study, COH = cohort study, RCT = randomised controlled trial.

*The study does not clearly state whether it refers to diabetes type 1, type 2 or both. We assume type 2 diabetes as the articles references refer to type 2 diabetes studies.

**The information is not provided in the study.

***Year of data collection could not be identified. Year of publication utilised as proxy.